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sqlite/ext/wasm/api/sqlite3-api-oo1.js

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/*
2022-07-22
The author disclaims copyright to this source code. In place of a
legal notice, here is a blessing:
* May you do good and not evil.
* May you find forgiveness for yourself and forgive others.
* May you share freely, never taking more than you give.
***********************************************************************
This file contains the so-called OO #1 API wrapper for the sqlite3
WASM build. It requires that sqlite3-api-glue.js has already run
and it installs its deliverable as globalThis.sqlite3.oo1.
*/
globalThis.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
const toss = (...args)=>{throw new Error(args.join(' '))};
const toss3 = (...args)=>{throw new sqlite3.SQLite3Error(...args)};
const capi = sqlite3.capi, wasm = sqlite3.wasm, util = sqlite3.util;
/* What follows is colloquially known as "OO API #1". It is a
binding of the sqlite3 API which is designed to be run within
the same thread (main or worker) as the one in which the
sqlite3 WASM binding was initialized. This wrapper cannot use
the sqlite3 binding if, e.g., the wrapper is in the main thread
and the sqlite3 API is in a worker. */
/**
In order to keep clients from manipulating, perhaps
inadvertently, the underlying pointer values of DB and Stmt
instances, we'll gate access to them via the `pointer` property
accessor and store their real values in this map. Keys = DB/Stmt
objects, values = pointer values. This also unifies how those are
accessed, for potential use downstream via custom
wasm.xWrap() function signatures which know how to extract
it.
*/
const __ptrMap = new WeakMap();
/**
Map of DB instances to objects, each object being a map of Stmt
wasm pointers to Stmt objects.
*/
const __stmtMap = new WeakMap();
/** If object opts has _its own_ property named p then that
property's value is returned, else dflt is returned. */
const getOwnOption = (opts, p, dflt)=>{
const d = Object.getOwnPropertyDescriptor(opts,p);
return d ? d.value : dflt;
};
// Documented in DB.checkRc()
const checkSqlite3Rc = function(dbPtr, sqliteResultCode){
if(sqliteResultCode){
if(dbPtr instanceof DB) dbPtr = dbPtr.pointer;
toss3(
sqliteResultCode,
"sqlite3 result code",sqliteResultCode+":",
(dbPtr
? capi.sqlite3_errmsg(dbPtr)
: capi.sqlite3_errstr(sqliteResultCode))
);
}
return arguments[0];
};
/**
sqlite3_trace_v2() callback which gets installed by the DB ctor
if its open-flags contain "t".
*/
const __dbTraceToConsole =
wasm.installFunction('i(ippp)', function(t,c,p,x){
if(capi.SQLITE_TRACE_STMT===t){
// x == SQL, p == sqlite3_stmt*
console.log("SQL TRACE #"+(++this.counter)+' via sqlite3@'+c+':',
wasm.cstrToJs(x));
}
}.bind({counter: 0}));
/**
A map of sqlite3_vfs pointers to SQL code or a callback function
to run when the DB constructor opens a database with the given
VFS. In the latter case, the call signature is (theDbObject,sqlite3Namespace)
and the callback is expected to throw on error.
*/
const __vfsPostOpenSql = Object.create(null);
/**
A proxy for DB class constructors. It must be called with the
being-construct DB object as its "this". See the DB constructor
for the argument docs. This is split into a separate function
in order to enable simple creation of special-case DB constructors,
e.g. JsStorageDb and OpfsDb.
Expects to be passed a configuration object with the following
properties:
- `.filename`: the db filename. It may be a special name like ":memory:"
or "".
- `.flags`: as documented in the DB constructor.
- `.vfs`: as documented in the DB constructor.
It also accepts those as the first 3 arguments.
*/
const dbCtorHelper = function ctor(...args){
if(!ctor._name2vfs){
/**
Map special filenames which we handle here (instead of in C)
to some helpful metadata...
As of 2022-09-20, the C API supports the names :localStorage:
and :sessionStorage: for kvvfs. However, C code cannot
determine (without embedded JS code, e.g. via Emscripten's
EM_JS()) whether the kvvfs is legal in the current browser
context (namely the main UI thread). In order to help client
code fail early on, instead of it being delayed until they
try to read or write a kvvfs-backed db, we'll check for those
names here and throw if they're not legal in the current
context.
*/
ctor._name2vfs = Object.create(null);
const isWorkerThread = ('function'===typeof importScripts/*===running in worker thread*/)
? (n)=>toss3("The VFS for",n,"is only available in the main window thread.")
: false;
ctor._name2vfs[':localStorage:'] = {
vfs: 'kvvfs', filename: isWorkerThread || (()=>'local')
};
ctor._name2vfs[':sessionStorage:'] = {
vfs: 'kvvfs', filename: isWorkerThread || (()=>'session')
};
}
const opt = ctor.normalizeArgs(...args);
let fn = opt.filename, vfsName = opt.vfs, flagsStr = opt.flags;
if(('string'!==typeof fn && 'number'!==typeof fn)
|| 'string'!==typeof flagsStr
|| (vfsName && ('string'!==typeof vfsName && 'number'!==typeof vfsName))){
sqlite3.config.error("Invalid DB ctor args",opt,arguments);
toss3("Invalid arguments for DB constructor.");
}
let fnJs = ('number'===typeof fn) ? wasm.cstrToJs(fn) : fn;
const vfsCheck = ctor._name2vfs[fnJs];
if(vfsCheck){
vfsName = vfsCheck.vfs;
fn = fnJs = vfsCheck.filename(fnJs);
}
let pDb, oflags = 0;
if( flagsStr.indexOf('c')>=0 ){
oflags |= capi.SQLITE_OPEN_CREATE | capi.SQLITE_OPEN_READWRITE;
}
if( flagsStr.indexOf('w')>=0 ) oflags |= capi.SQLITE_OPEN_READWRITE;
if( 0===oflags ) oflags |= capi.SQLITE_OPEN_READONLY;
oflags |= capi.SQLITE_OPEN_EXRESCODE;
const stack = wasm.pstack.pointer;
try {
const pPtr = wasm.pstack.allocPtr() /* output (sqlite3**) arg */;
let rc = capi.sqlite3_open_v2(fn, pPtr, oflags, vfsName || 0);
pDb = wasm.peekPtr(pPtr);
checkSqlite3Rc(pDb, rc);
capi.sqlite3_extended_result_codes(pDb, 1);
if(flagsStr.indexOf('t')>=0){
capi.sqlite3_trace_v2(pDb, capi.SQLITE_TRACE_STMT,
__dbTraceToConsole, pDb);
}
}catch( e ){
if( pDb ) capi.sqlite3_close_v2(pDb);
throw e;
}finally{
wasm.pstack.restore(stack);
}
this.filename = fnJs;
__ptrMap.set(this, pDb);
__stmtMap.set(this, Object.create(null));
try{
// Check for per-VFS post-open SQL/callback...
const pVfs = capi.sqlite3_js_db_vfs(pDb);
if(!pVfs) toss3("Internal error: cannot get VFS for new db handle.");
const postInitSql = __vfsPostOpenSql[pVfs];
if(postInitSql instanceof Function){
postInitSql(this, sqlite3);
}else if(postInitSql){
checkSqlite3Rc(
pDb, capi.sqlite3_exec(pDb, postInitSql, 0, 0, 0)
);
}
}catch(e){
this.close();
throw e;
}
};
/**
Sets SQL which should be exec()'d on a DB instance after it is
opened with the given VFS pointer. The SQL may be any type
supported by the "string:flexible" function argument conversion.
Alternately, the 2nd argument may be a function, in which case it
is called with (theOo1DbObject,sqlite3Namespace) at the end of
the DB() constructor. The function must throw on error, in which
case the db is closed and the exception is propagated. This
function is intended only for use by DB subclasses or sqlite3_vfs
implementations.
*/
dbCtorHelper.setVfsPostOpenSql = function(pVfs, sql){
__vfsPostOpenSql[pVfs] = sql;
};
/**
A helper for DB constructors. It accepts either a single
config-style object or up to 3 arguments (filename, dbOpenFlags,
dbVfsName). It returns a new object containing:
{ filename: ..., flags: ..., vfs: ... }
If passed an object, any additional properties it has are copied
as-is into the new object.
*/
dbCtorHelper.normalizeArgs = function(filename=':memory:',flags = 'c',vfs = null){
const arg = {};
if(1===arguments.length && arguments[0] && 'object'===typeof arguments[0]){
Object.assign(arg, arguments[0]);
if(undefined===arg.flags) arg.flags = 'c';
if(undefined===arg.vfs) arg.vfs = null;
if(undefined===arg.filename) arg.filename = ':memory:';
}else{
arg.filename = filename;
arg.flags = flags;
arg.vfs = vfs;
}
return arg;
};
/**
The DB class provides a high-level OO wrapper around an sqlite3
db handle.
The given db filename must be resolvable using whatever
filesystem layer (virtual or otherwise) is set up for the default
sqlite3 VFS.
Note that the special sqlite3 db names ":memory:" and ""
(temporary db) have their normal special meanings here and need
not resolve to real filenames, but "" uses an on-storage
temporary database and requires that the VFS support that.
The second argument specifies the open/create mode for the
database. It must be string containing a sequence of letters (in
any order, but case sensitive) specifying the mode:
- "c": create if it does not exist, else fail if it does not
exist. Implies the "w" flag.
- "w": write. Implies "r": a db cannot be write-only.
- "r": read-only if neither "w" nor "c" are provided, else it
is ignored.
- "t": enable tracing of SQL executed on this database handle,
sending it to `console.log()`. To disable it later, call
`sqlite3.capi.sqlite3_trace_v2(thisDb.pointer, 0, 0, 0)`.
If "w" is not provided, the db is implicitly read-only, noting
that "rc" is meaningless
Any other letters are currently ignored. The default is
"c". These modes are ignored for the special ":memory:" and ""
names and _may_ be ignored altogether for certain VFSes.
The final argument is analogous to the final argument of
sqlite3_open_v2(): the name of an sqlite3 VFS. Pass a falsy value,
or none at all, to use the default. If passed a value, it must
be the string name of a VFS.
The constructor optionally (and preferably) takes its arguments
in the form of a single configuration object with the following
properties:
- `filename`: database file name
- `flags`: open-mode flags
- `vfs`: the VFS fname
The `filename` and `vfs` arguments may be either JS strings or
C-strings allocated via WASM. `flags` is required to be a JS
string (because it's specific to this API, which is specific
to JS).
For purposes of passing a DB instance to C-style sqlite3
functions, the DB object's read-only `pointer` property holds its
`sqlite3*` pointer value. That property can also be used to check
whether this DB instance is still open.
In the main window thread, the filenames `":localStorage:"` and
`":sessionStorage:"` are special: they cause the db to use either
localStorage or sessionStorage for storing the database using
the kvvfs. If one of these names are used, they trump
any vfs name set in the arguments.
*/
const DB = function(...args){
dbCtorHelper.apply(this, args);
};
DB.dbCtorHelper = dbCtorHelper;
/**
Internal-use enum for mapping JS types to DB-bindable types.
These do not (and need not) line up with the SQLITE_type
values. All values in this enum must be truthy and distinct
but they need not be numbers.
*/
const BindTypes = {
null: 1,
number: 2,
string: 3,
boolean: 4,
blob: 5
};
BindTypes['undefined'] == BindTypes.null;
if(wasm.bigIntEnabled){
BindTypes.bigint = BindTypes.number;
}
/**
This class wraps sqlite3_stmt. Calling this constructor
directly will trigger an exception. Use DB.prepare() to create
new instances.
For purposes of passing a Stmt instance to C-style sqlite3
functions, its read-only `pointer` property holds its `sqlite3_stmt*`
pointer value.
Other non-function properties include:
- `db`: the DB object which created the statement.
- `columnCount`: the number of result columns in the query, or 0
for queries which cannot return results. This property is a proxy
for sqlite3_column_count() and its use in loops should be avoided
because of the call overhead associated with that. The
`columnCount` is not cached when the Stmt is created because a
schema change made via a separate db connection between this
statement's preparation and when it is stepped may invalidate it.
- `parameterCount`: the number of bindable parameters in the query.
*/
const Stmt = function(){
if(BindTypes!==arguments[2]){
toss3(capi.SQLITE_MISUSE, "Do not call the Stmt constructor directly. Use DB.prepare().");
}
this.db = arguments[0];
__ptrMap.set(this, arguments[1]);
this.parameterCount = capi.sqlite3_bind_parameter_count(this.pointer);
};
/** Throws if the given DB has been closed, else it is returned. */
const affirmDbOpen = function(db){
if(!db.pointer) toss3("DB has been closed.");
return db;
};
/** Throws if ndx is not an integer or if it is out of range
for stmt.columnCount, else returns stmt.
Reminder: this will also fail after the statement is finalized
but the resulting error will be about an out-of-bounds column
index rather than a statement-is-finalized error.
*/
const affirmColIndex = function(stmt,ndx){
if((ndx !== (ndx|0)) || ndx<0 || ndx>=stmt.columnCount){
toss3("Column index",ndx,"is out of range.");
}
return stmt;
};
/**
Expects to be passed the `arguments` object from DB.exec(). Does
the argument processing/validation, throws on error, and returns
a new object on success:
{ sql: the SQL, opt: optionsObj, cbArg: function}
The opt object is a normalized copy of any passed to this
function. The sql will be converted to a string if it is provided
in one of the supported non-string formats.
cbArg is only set if the opt.callback or opt.resultRows are set,
in which case it's a function which expects to be passed the
current Stmt and returns the callback argument of the type
indicated by the input arguments.
*/
const parseExecArgs = function(db, args){
const out = Object.create(null);
out.opt = Object.create(null);
switch(args.length){
case 1:
if('string'===typeof args[0] || util.isSQLableTypedArray(args[0])){
out.sql = args[0];
}else if(Array.isArray(args[0])){
out.sql = args[0];
}else if(args[0] && 'object'===typeof args[0]){
out.opt = args[0];
out.sql = out.opt.sql;
}
break;
case 2:
out.sql = args[0];
out.opt = args[1];
break;
default: toss3("Invalid argument count for exec().");
};
out.sql = util.flexibleString(out.sql);
if('string'!==typeof out.sql){
toss3("Missing SQL argument or unsupported SQL value type.");
}
const opt = out.opt;
switch(opt.returnValue){
case 'resultRows':
if(!opt.resultRows) opt.resultRows = [];
out.returnVal = ()=>opt.resultRows;
break;
case 'saveSql':
if(!opt.saveSql) opt.saveSql = [];
out.returnVal = ()=>opt.saveSql;
break;
case undefined:
case 'this':
out.returnVal = ()=>db;
break;
default:
toss3("Invalid returnValue value:",opt.returnValue);
}
if(!opt.callback && !opt.returnValue && undefined!==opt.rowMode){
if(!opt.resultRows) opt.resultRows = [];
out.returnVal = ()=>opt.resultRows;
}
if(opt.callback || opt.resultRows){
switch((undefined===opt.rowMode)
? 'array' : opt.rowMode) {
case 'object': out.cbArg = (stmt)=>stmt.get(Object.create(null)); break;
case 'array': out.cbArg = (stmt)=>stmt.get([]); break;
case 'stmt':
if(Array.isArray(opt.resultRows)){
toss3("exec(): invalid rowMode for a resultRows array: must",
"be one of 'array', 'object',",
"a result column number, or column name reference.");
}
out.cbArg = (stmt)=>stmt;
break;
default:
if(util.isInt32(opt.rowMode)){
out.cbArg = (stmt)=>stmt.get(opt.rowMode);
break;
}else if('string'===typeof opt.rowMode
&& opt.rowMode.length>1
&& '$'===opt.rowMode[0]){
/* "$X": fetch column named "X" (case-sensitive!). Prior
to 2022-12-14 ":X" and "@X" were also permitted, but
having so many options is unnecessary and likely to
cause confusion. */
const $colName = opt.rowMode.substr(1);
out.cbArg = (stmt)=>{
const rc = stmt.get(Object.create(null))[$colName];
return (undefined===rc)
? toss3(capi.SQLITE_NOTFOUND,
"exec(): unknown result column:",$colName)
: rc;
};
break;
}
toss3("Invalid rowMode:",opt.rowMode);
}
}
return out;
};
/**
Internal impl of the DB.selectValue(), selectArray(), and
selectObject() methods.
*/
const __selectFirstRow = (db, sql, bind, ...getArgs)=>{
const stmt = db.prepare(sql);
try {
const rc = stmt.bind(bind).step() ? stmt.get(...getArgs) : undefined;
stmt.reset(/*for INSERT...RETURNING locking case*/);
return rc;
}finally{
stmt.finalize();
}
};
/**
Internal impl of the DB.selectArrays() and selectObjects()
methods.
*/
const __selectAll =
(db, sql, bind, rowMode)=>db.exec({
sql, bind, rowMode, returnValue: 'resultRows'
});
/**
Expects to be given a DB instance or an `sqlite3*` pointer (may
be null) and an sqlite3 API result code. If the result code is
not falsy, this function throws an SQLite3Error with an error
message from sqlite3_errmsg(), using db (or, if db is-a DB,
db.pointer) as the db handle, or sqlite3_errstr() if db is
falsy. Note that if it's passed a non-error code like SQLITE_ROW
or SQLITE_DONE, it will still throw but the error string might be
"Not an error." The various non-0 non-error codes need to be
checked for in client code where they are expected.
The thrown exception's `resultCode` property will be the value of
the second argument to this function.
If it does not throw, it returns its first argument.
*/
DB.checkRc = (db,resultCode)=>checkSqlite3Rc(db,resultCode);
DB.prototype = {
/** Returns true if this db handle is open, else false. */
isOpen: function(){
return !!this.pointer;
},
/** Throws if this given DB has been closed, else returns `this`. */
affirmOpen: function(){
return affirmDbOpen(this);
},
/**
Finalizes all open statements and closes this database
connection. This is a no-op if the db has already been
closed. After calling close(), `this.pointer` will resolve to
`undefined`, so that can be used to check whether the db
instance is still opened.
If this.onclose.before is a function then it is called before
any close-related cleanup.
If this.onclose.after is a function then it is called after the
db is closed but before auxiliary state like this.filename is
cleared.
Both onclose handlers are passed this object, with the onclose
object as their "this," noting that the db will have been
closed when onclose.after is called. If this db is not opened
when close() is called, neither of the handlers are called. Any
exceptions the handlers throw are ignored because "destructors
must not throw."
Note that garbage collection of a db handle, if it happens at
all, will never trigger close(), so onclose handlers are not a
reliable way to implement close-time cleanup or maintenance of
a db.
*/
close: function(){
if(this.pointer){
if(this.onclose && (this.onclose.before instanceof Function)){
try{this.onclose.before(this)}
catch(e){/*ignore*/}
}
const pDb = this.pointer;
Object.keys(__stmtMap.get(this)).forEach((k,s)=>{
if(s && s.pointer){
try{s.finalize()}
catch(e){/*ignore*/}
}
});
__ptrMap.delete(this);
__stmtMap.delete(this);
capi.sqlite3_close_v2(pDb);
if(this.onclose && (this.onclose.after instanceof Function)){
try{this.onclose.after(this)}
catch(e){/*ignore*/}
}
delete this.filename;
}
},
/**
Returns the number of changes, as per sqlite3_changes()
(if the first argument is false) or sqlite3_total_changes()
(if it's true). If the 2nd argument is true, it uses
sqlite3_changes64() or sqlite3_total_changes64(), which
will trigger an exception if this build does not have
BigInt support enabled.
*/
changes: function(total=false,sixtyFour=false){
const p = affirmDbOpen(this).pointer;
if(total){
return sixtyFour
? capi.sqlite3_total_changes64(p)
: capi.sqlite3_total_changes(p);
}else{
return sixtyFour
? capi.sqlite3_changes64(p)
: capi.sqlite3_changes(p);
}
},
/**
Similar to the this.filename but returns the
sqlite3_db_filename() value for the given database name,
defaulting to "main". The argument may be either a JS string
or a pointer to a WASM-allocated C-string.
*/
dbFilename: function(dbName='main'){
return capi.sqlite3_db_filename(affirmDbOpen(this).pointer, dbName);
},
/**
Returns the name of the given 0-based db number, as documented
for sqlite3_db_name().
*/
dbName: function(dbNumber=0){
return capi.sqlite3_db_name(affirmDbOpen(this).pointer, dbNumber);
},
/**
Returns the name of the sqlite3_vfs used by the given database
of this connection (defaulting to 'main'). The argument may be
either a JS string or a WASM C-string. Returns undefined if the
given db name is invalid. Throws if this object has been
close()d.
*/
dbVfsName: function(dbName=0){
let rc;
const pVfs = capi.sqlite3_js_db_vfs(
affirmDbOpen(this).pointer, dbName
);
if(pVfs){
const v = new capi.sqlite3_vfs(pVfs);
try{ rc = wasm.cstrToJs(v.$zName) }
finally { v.dispose() }
}
return rc;
},
/**
Compiles the given SQL and returns a prepared Stmt. This is
the only way to create new Stmt objects. Throws on error.
The given SQL must be a string, a Uint8Array holding SQL, a
WASM pointer to memory holding the NUL-terminated SQL string,
or an array of strings. In the latter case, the array is
concatenated together, with no separators, to form the SQL
string (arrays are often a convenient way to formulate long
statements). If the SQL contains no statements, an
SQLite3Error is thrown.
Design note: the C API permits empty SQL, reporting it as a 0
result code and a NULL stmt pointer. Supporting that case here
would cause extra work for all clients: any use of the Stmt API
on such a statement will necessarily throw, so clients would be
required to check `stmt.pointer` after calling `prepare()` in
order to determine whether the Stmt instance is empty or not.
Long-time practice (with other sqlite3 script bindings)
suggests that the empty-prepare case is sufficiently rare that
supporting it here would simply hurt overall usability.
*/
prepare: function(sql){
affirmDbOpen(this);
const stack = wasm.pstack.pointer;
let ppStmt, pStmt;
try{
ppStmt = wasm.pstack.alloc(8)/* output (sqlite3_stmt**) arg */;
DB.checkRc(this, capi.sqlite3_prepare_v2(this.pointer, sql, -1, ppStmt, null));
pStmt = wasm.peekPtr(ppStmt);
}
finally {
wasm.pstack.restore(stack);
}
if(!pStmt) toss3("Cannot prepare empty SQL.");
const stmt = new Stmt(this, pStmt, BindTypes);
__stmtMap.get(this)[pStmt] = stmt;
return stmt;
},
/**
Executes one or more SQL statements in the form of a single
string. Its arguments must be either (sql,optionsObject) or
(optionsObject). In the latter case, optionsObject.sql must
contain the SQL to execute. By default it returns this object
but that can be changed via the `returnValue` option as
described below. Throws on error.
If no SQL is provided, or a non-string is provided, an
exception is triggered. Empty SQL, on the other hand, is
simply a no-op.
The optional options object may contain any of the following
properties:
- `sql` = the SQL to run (unless it's provided as the first
argument). This must be of type string, Uint8Array, or an array
of strings. In the latter case they're concatenated together
as-is, _with no separator_ between elements, before evaluation.
The array form is often simpler for long hand-written queries.
- `bind` = a single value valid as an argument for
Stmt.bind(). This is _only_ applied to the _first_ non-empty
statement in the SQL which has any bindable parameters. (Empty
statements are skipped entirely.)
- `saveSql` = an optional array. If set, the SQL of each
executed statement is appended to this array before the
statement is executed (but after it is prepared - we don't have
the string until after that). Empty SQL statements are elided
but can have odd effects in the output. e.g. SQL of: `"select
1; -- empty\n; select 2"` will result in an array containing
`["select 1;", "--empty \n; select 2"]`. That's simply how
sqlite3 records the SQL for the 2nd statement.
==================================================================
The following options apply _only_ to the _first_ statement
which has a non-zero result column count, regardless of whether
the statement actually produces any result rows.
==================================================================
- `columnNames`: if this is an array, the column names of the
result set are stored in this array before the callback (if
any) is triggered (regardless of whether the query produces any
result rows). If no statement has result columns, this value is
unchanged. Achtung: an SQL result may have multiple columns
with identical names.
- `callback` = a function which gets called for each row of the
result set, but only if that statement has any result rows. The
callback's "this" is the options object, noting that this
function synthesizes one if the caller does not pass one to
exec(). The second argument passed to the callback is always
the current Stmt object, as it's needed if the caller wants to
fetch the column names or some such (noting that they could
also be fetched via `this.columnNames`, if the client provides
the `columnNames` option). If the callback returns a literal
`false` (as opposed to any other falsy value, e.g. an implicit
`undefined` return), any ongoing statement-`step()` iteration
stops without an error. The return value of the callback is
otherwise ignored.
ACHTUNG: The callback MUST NOT modify the Stmt object. Calling
any of the Stmt.get() variants, Stmt.getColumnName(), or
similar, is legal, but calling step() or finalize() is
not. Member methods which are illegal in this context will
trigger an exception, but clients must also refrain from using
any lower-level (C-style) APIs which might modify the
statement.
The first argument passed to the callback defaults to an array of
values from the current result row but may be changed with ...
- `rowMode` = specifies the type of he callback's first argument.
It may be any of...
A) A string describing what type of argument should be passed
as the first argument to the callback:
A.1) `'array'` (the default) causes the results of
`stmt.get([])` to be passed to the `callback` and/or appended
to `resultRows`.
A.2) `'object'` causes the results of
`stmt.get(Object.create(null))` to be passed to the
`callback` and/or appended to `resultRows`. Achtung: an SQL
result may have multiple columns with identical names. In
that case, the right-most column will be the one set in this
object!
A.3) `'stmt'` causes the current Stmt to be passed to the
callback, but this mode will trigger an exception if
`resultRows` is an array because appending the transient
statement to the array would be downright unhelpful.
B) An integer, indicating a zero-based column in the result
row. Only that one single value will be passed on.
C) A string with a minimum length of 2 and leading character of
'$' will fetch the row as an object, extract that one field,
and pass that field's value to the callback. Note that these
keys are case-sensitive so must match the case used in the
SQL. e.g. `"select a A from t"` with a `rowMode` of `'$A'`
would work but `'$a'` would not. A reference to a column not in
the result set will trigger an exception on the first row (as
the check is not performed until rows are fetched). Note also
that `$` is a legal identifier character in JS so need not be
quoted.
Any other `rowMode` value triggers an exception.
- `resultRows`: if this is an array, it functions similarly to
the `callback` option: each row of the result set (if any),
with the exception that the `rowMode` 'stmt' is not legal. It
is legal to use both `resultRows` and `callback`, but
`resultRows` is likely much simpler to use for small data sets
and can be used over a WebWorker-style message interface.
exec() throws if `resultRows` is set and `rowMode` is 'stmt'.
- `returnValue`: is a string specifying what this function
should return:
A) The default value is (usually) `"this"`, meaning that the
DB object itself should be returned. The exception is if
the caller passes neither of `callback` nor `returnValue`
but does pass an explicit `rowMode` then the default
`returnValue` is `"resultRows"`, described below.
B) `"resultRows"` means to return the value of the
`resultRows` option. If `resultRows` is not set, this
function behaves as if it were set to an empty array.
C) `"saveSql"` means to return the value of the
`saveSql` option. If `saveSql` is not set, this
function behaves as if it were set to an empty array.
Potential TODOs:
- `bind`: permit an array of arrays/objects to bind. The first
sub-array would act on the first statement which has bindable
parameters (as it does now). The 2nd would act on the next such
statement, etc.
- `callback` and `resultRows`: permit an array entries with
semantics similar to those described for `bind` above.
*/
exec: function(/*(sql [,obj]) || (obj)*/){
affirmDbOpen(this);
const arg = parseExecArgs(this, arguments);
if(!arg.sql){
return toss3("exec() requires an SQL string.");
}
const opt = arg.opt;
const callback = opt.callback;
const resultRows =
Array.isArray(opt.resultRows) ? opt.resultRows : undefined;
let stmt;
let bind = opt.bind;
let evalFirstResult = !!(
arg.cbArg || opt.columnNames || resultRows
) /* true to step through the first result-returning statement */;
const stack = wasm.scopedAllocPush();
const saveSql = Array.isArray(opt.saveSql) ? opt.saveSql : undefined;
try{
const isTA = util.isSQLableTypedArray(arg.sql)
/* Optimization: if the SQL is a TypedArray we can save some string
conversion costs. */;
/* Allocate the two output pointers (ppStmt, pzTail) and heap
space for the SQL (pSql). When prepare_v2() returns, pzTail
will point to somewhere in pSql. */
let sqlByteLen = isTA ? arg.sql.byteLength : wasm.jstrlen(arg.sql);
const ppStmt = wasm.scopedAlloc(
/* output (sqlite3_stmt**) arg and pzTail */
(2 * wasm.ptrSizeof) + (sqlByteLen + 1/* SQL + NUL */)
);
const pzTail = ppStmt + wasm.ptrSizeof /* final arg to sqlite3_prepare_v2() */;
let pSql = pzTail + wasm.ptrSizeof;
const pSqlEnd = pSql + sqlByteLen;
if(isTA) wasm.heap8().set(arg.sql, pSql);
else wasm.jstrcpy(arg.sql, wasm.heap8(), pSql, sqlByteLen, false);
wasm.poke(pSql + sqlByteLen, 0/*NUL terminator*/);
while(pSql && wasm.peek(pSql, 'i8')
/* Maintenance reminder:^^^ _must_ be 'i8' or else we
will very likely cause an endless loop. What that's
doing is checking for a terminating NUL byte. If we
use i32 or similar then we read 4 bytes, read stuff
around the NUL terminator, and get stuck in and
endless loop at the end of the SQL, endlessly
re-preparing an empty statement. */ ){
wasm.pokePtr([ppStmt, pzTail], 0);
DB.checkRc(this, capi.sqlite3_prepare_v3(
this.pointer, pSql, sqlByteLen, 0, ppStmt, pzTail
));
const pStmt = wasm.peekPtr(ppStmt);
pSql = wasm.peekPtr(pzTail);
sqlByteLen = pSqlEnd - pSql;
if(!pStmt) continue;
if(saveSql) saveSql.push(capi.sqlite3_sql(pStmt).trim());
stmt = new Stmt(this, pStmt, BindTypes);
if(bind && stmt.parameterCount){
stmt.bind(bind);
bind = null;
}
if(evalFirstResult && stmt.columnCount){
/* Only forward SELECT-style results for the FIRST query
in the SQL which potentially has them. */
let gotColNames = Array.isArray(
opt.columnNames
/* As reported in
https://sqlite.org/forum/forumpost/7774b773937cbe0a
we need to delay fetching of the column names until
after the first step() (if we step() at all) because
a schema change between the prepare() and step(), via
another connection, may invalidate the column count
and names. */) ? 0 : 1;
evalFirstResult = false;
if(arg.cbArg || resultRows){
for(; stmt.step(); stmt._lockedByExec = false){
if(0===gotColNames++) stmt.getColumnNames(opt.columnNames);
stmt._lockedByExec = true;
const row = arg.cbArg(stmt);
if(resultRows) resultRows.push(row);
if(callback && false === callback.call(opt, row, stmt)){
break;
}
}
stmt._lockedByExec = false;
}
if(0===gotColNames){
/* opt.columnNames was provided but we visited no result rows */
stmt.getColumnNames(opt.columnNames);
}
}else{
stmt.step();
}
stmt.reset(
/* In order to trigger an exception in the
INSERT...RETURNING locking scenario:
https://sqlite.org/forum/forumpost/36f7a2e7494897df
*/).finalize();
stmt = null;
}/*prepare() loop*/
}/*catch(e){
sqlite3.config.warn("DB.exec() is propagating exception",opt,e);
throw e;
}*/finally{
wasm.scopedAllocPop(stack);
if(stmt){
delete stmt._lockedByExec;
stmt.finalize();
}
}
return arg.returnVal();
}/*exec()*/,
/**
Creates a new UDF (User-Defined Function) which is accessible
via SQL code. This function may be called in any of the
following forms:
- (name, function)
- (name, function, optionsObject)
- (name, optionsObject)
- (optionsObject)
In the final two cases, the function must be defined as the
`callback` property of the options object (optionally called
`xFunc` to align with the C API documentation). In the final
case, the function's name must be the 'name' property.
The first two call forms can only be used for creating scalar
functions. Creating an aggregate or window function requires
the options-object form (see below for details).
UDFs can be removed as documented for
sqlite3_create_function_v2() and
sqlite3_create_window_function(), but doing so will "leak" the
JS-created WASM binding of those functions (meaning that their
entries in the WASM indirect function table still
exist). Eliminating that potential leak is a pending TODO.
On success, returns this object. Throws on error.
When called from SQL arguments to the UDF, and its result,
will be converted between JS and SQL with as much fidelity as
is feasible, triggering an exception if a type conversion
cannot be determined. The docs for sqlite3_create_function_v2()
describe the conversions in more detail.
The values set in the options object differ for scalar and
aggregate functions:
- Scalar: set the `xFunc` function-type property to the UDF
function.
- Aggregate: set the `xStep` and `xFinal` function-type
properties to the "step" and "final" callbacks for the
aggregate. Do not set the `xFunc` property.
- Window: set the `xStep`, `xFinal`, `xValue`, and `xInverse`
function-type properties. Do not set the `xFunc` property.
The options object may optionally have an `xDestroy`
function-type property, as per sqlite3_create_function_v2().
Its argument will be the WASM-pointer-type value of the `pApp`
property, and this function will throw if `pApp` is defined but
is not null, undefined, or a numeric (WASM pointer)
value. i.e. `pApp`, if set, must be value suitable for use as a
WASM pointer argument, noting that `null` or `undefined` will
translate to 0 for that purpose.
The options object may contain flags to modify how
the function is defined:
- `arity`: the number of arguments which SQL calls to this
function expect or require. The default value is `xFunc.length`
or `xStep.length` (i.e. the number of declared parameters it
has) **MINUS 1** (see below for why). As a special case, if the
`length` is 0, its arity is also 0 instead of -1. A negative
arity value means that the function is variadic and may accept
any number of arguments, up to sqlite3's compile-time
limits. sqlite3 will enforce the argument count if is zero or
greater. The callback always receives a pointer to an
`sqlite3_context` object as its first argument. Any arguments
after that are from SQL code. The leading context argument does
_not_ count towards the function's arity. See the docs for
sqlite3.capi.sqlite3_create_function_v2() for why that argument
is needed in the interface.
The following options-object properties correspond to flags
documented at:
https://sqlite.org/c3ref/create_function.html
- `deterministic` = sqlite3.capi.SQLITE_DETERMINISTIC
- `directOnly` = sqlite3.capi.SQLITE_DIRECTONLY
- `innocuous` = sqlite3.capi.SQLITE_INNOCUOUS
Sidebar: the ability to add new WASM-accessible functions to
the runtime requires that the WASM build is compiled with the
equivalent functionality as that provided by Emscripten's
`-sALLOW_TABLE_GROWTH` flag.
*/
createFunction: function f(name, xFunc, opt){
const isFunc = (f)=>(f instanceof Function);
switch(arguments.length){
case 1: /* (optionsObject) */
opt = name;
name = opt.name;
xFunc = opt.xFunc || 0;
break;
case 2: /* (name, callback|optionsObject) */
if(!isFunc(xFunc)){
opt = xFunc;
xFunc = opt.xFunc || 0;
}
break;
case 3: /* name, xFunc, opt */
break;
default: break;
}
if(!opt) opt = {};
if('string' !== typeof name){
toss3("Invalid arguments: missing function name.");
}
let xStep = opt.xStep || 0;
let xFinal = opt.xFinal || 0;
const xValue = opt.xValue || 0;
const xInverse = opt.xInverse || 0;
let isWindow = undefined;
if(isFunc(xFunc)){
isWindow = false;
if(isFunc(xStep) || isFunc(xFinal)){
toss3("Ambiguous arguments: scalar or aggregate?");
}
xStep = xFinal = null;
}else if(isFunc(xStep)){
if(!isFunc(xFinal)){
toss3("Missing xFinal() callback for aggregate or window UDF.");
}
xFunc = null;
}else if(isFunc(xFinal)){
toss3("Missing xStep() callback for aggregate or window UDF.");
}else{
toss3("Missing function-type properties.");
}
if(false === isWindow){
if(isFunc(xValue) || isFunc(xInverse)){
toss3("xValue and xInverse are not permitted for non-window UDFs.");
}
}else if(isFunc(xValue)){
if(!isFunc(xInverse)){
toss3("xInverse must be provided if xValue is.");
}
isWindow = true;
}else if(isFunc(xInverse)){
toss3("xValue must be provided if xInverse is.");
}
const pApp = opt.pApp;
if(undefined!==pApp &&
null!==pApp &&
(('number'!==typeof pApp) || !util.isInt32(pApp))){
toss3("Invalid value for pApp property. Must be a legal WASM pointer value.");
}
const xDestroy = opt.xDestroy || 0;
if(xDestroy && !isFunc(xDestroy)){
toss3("xDestroy property must be a function.");
}
let fFlags = 0 /*flags for sqlite3_create_function_v2()*/;
if(getOwnOption(opt, 'deterministic')) fFlags |= capi.SQLITE_DETERMINISTIC;
if(getOwnOption(opt, 'directOnly')) fFlags |= capi.SQLITE_DIRECTONLY;
if(getOwnOption(opt, 'innocuous')) fFlags |= capi.SQLITE_INNOCUOUS;
name = name.toLowerCase();
const xArity = xFunc || xStep;
const arity = getOwnOption(opt, 'arity');
const arityArg = ('number'===typeof arity
? arity
: (xArity.length ? xArity.length-1/*for pCtx arg*/ : 0));
let rc;
if( isWindow ){
rc = capi.sqlite3_create_window_function(
this.pointer, name, arityArg,
capi.SQLITE_UTF8 | fFlags, pApp || 0,
xStep, xFinal, xValue, xInverse, xDestroy);
}else{
rc = capi.sqlite3_create_function_v2(
this.pointer, name, arityArg,
capi.SQLITE_UTF8 | fFlags, pApp || 0,
xFunc, xStep, xFinal, xDestroy);
}
DB.checkRc(this, rc);
return this;
}/*createFunction()*/,
/**
Prepares the given SQL, step()s it one time, and returns
the value of the first result column. If it has no results,
undefined is returned.
If passed a second argument, it is treated like an argument
to Stmt.bind(), so may be any type supported by that
function. Passing the undefined value is the same as passing
no value, which is useful when...
If passed a 3rd argument, it is expected to be one of the
SQLITE_{typename} constants. Passing the undefined value is
the same as not passing a value.
Throws on error (e.g. malformed SQL).
*/
selectValue: function(sql,bind,asType){
return __selectFirstRow(this, sql, bind, 0, asType);
},
/**
Runs the given query and returns an array of the values from
the first result column of each row of the result set. The 2nd
argument is an optional value for use in a single-argument call
to Stmt.bind(). The 3rd argument may be any value suitable for
use as the 2nd argument to Stmt.get(). If a 3rd argument is
desired but no bind data are needed, pass `undefined` for the 2nd
argument.
If there are no result rows, an empty array is returned.
*/
selectValues: function(sql,bind,asType){
const stmt = this.prepare(sql), rc = [];
try {
stmt.bind(bind);
while(stmt.step()) rc.push(stmt.get(0,asType));
stmt.reset(/*for INSERT...RETURNING locking case*/);
}finally{
stmt.finalize();
}
return rc;
},
/**
Prepares the given SQL, step()s it one time, and returns an
array containing the values of the first result row. If it has
no results, `undefined` is returned.
If passed a second argument other than `undefined`, it is
treated like an argument to Stmt.bind(), so may be any type
supported by that function.
Throws on error (e.g. malformed SQL).
*/
selectArray: function(sql,bind){
return __selectFirstRow(this, sql, bind, []);
},
/**
Prepares the given SQL, step()s it one time, and returns an
object containing the key/value pairs of the first result
row. If it has no results, `undefined` is returned.
Note that the order of returned object's keys is not guaranteed
to be the same as the order of the fields in the query string.
If passed a second argument other than `undefined`, it is
treated like an argument to Stmt.bind(), so may be any type
supported by that function.
Throws on error (e.g. malformed SQL).
*/
selectObject: function(sql,bind){
return __selectFirstRow(this, sql, bind, {});
},
/**
Runs the given SQL and returns an array of all results, with
each row represented as an array, as per the 'array' `rowMode`
option to `exec()`. An empty result set resolves
to an empty array. The second argument, if any, is treated as
the 'bind' option to a call to exec().
*/
selectArrays: function(sql,bind){
return __selectAll(this, sql, bind, 'array');
},
/**
Works identically to selectArrays() except that each value
in the returned array is an object, as per the 'object' `rowMode`
option to `exec()`.
*/
selectObjects: function(sql,bind){
return __selectAll(this, sql, bind, 'object');
},
/**
Returns the number of currently-opened Stmt handles for this db
handle, or 0 if this DB instance is closed. Note that only
handles prepared via this.prepare() are counted, and not
handles prepared using capi.sqlite3_prepare_v3() (or
equivalent).
*/
openStatementCount: function(){
return this.pointer ? Object.keys(__stmtMap.get(this)).length : 0;
},
/**
Starts a transaction, calls the given callback, and then either
rolls back or commits the savepoint, depending on whether the
callback throws. The callback is passed this db object as its
only argument. On success, returns the result of the
callback. Throws on error.
Note that transactions may not be nested, so this will throw if
it is called recursively. For nested transactions, use the
savepoint() method or manually manage SAVEPOINTs using exec().
If called with 2 arguments, the first must be a keyword which
is legal immediately after a BEGIN statement, e.g. one of
"DEFERRED", "IMMEDIATE", or "EXCLUSIVE". Though the exact list
of supported keywords is not hard-coded here, in order to be
future-compatible, if the argument does not look like a single
keyword then an exception is triggered with a description of
the problem.
*/
transaction: function(/* [beginQualifier,] */callback){
let opener = 'BEGIN';
if(arguments.length>1){
if(/[^a-zA-Z]/.test(arguments[0])){
toss3(capi.SQLITE_MISUSE, "Invalid argument for BEGIN qualifier.");
}
opener += ' '+arguments[0];
callback = arguments[1];
}
affirmDbOpen(this).exec(opener);
try {
const rc = callback(this);
this.exec("COMMIT");
return rc;
}catch(e){
this.exec("ROLLBACK");
throw e;
}
},
/**
This works similarly to transaction() but uses sqlite3's SAVEPOINT
feature. This function starts a savepoint (with an unspecified name)
and calls the given callback function, passing it this db object.
If the callback returns, the savepoint is released (committed). If
the callback throws, the savepoint is rolled back. If it does not
throw, it returns the result of the callback.
*/
savepoint: function(callback){
affirmDbOpen(this).exec("SAVEPOINT oo1");
try {
const rc = callback(this);
this.exec("RELEASE oo1");
return rc;
}catch(e){
this.exec("ROLLBACK to SAVEPOINT oo1; RELEASE SAVEPOINT oo1");
throw e;
}
},
/**
A convenience form of DB.checkRc(this,resultCode). If it does
not throw, it returns this object.
*/
checkRc: function(resultCode){
return checkSqlite3Rc(this, resultCode);
}
}/*DB.prototype*/;
/** Throws if the given Stmt has been finalized, else stmt is
returned. */
const affirmStmtOpen = function(stmt){
if(!stmt.pointer) toss3("Stmt has been closed.");
return stmt;
};
/** Returns an opaque truthy value from the BindTypes
enum if v's type is a valid bindable type, else
returns a falsy value. As a special case, a value of
undefined is treated as a bind type of null. */
const isSupportedBindType = function(v){
let t = BindTypes[(null===v||undefined===v) ? 'null' : typeof v];
switch(t){
case BindTypes.boolean:
case BindTypes.null:
case BindTypes.number:
case BindTypes.string:
return t;
case BindTypes.bigint:
if(wasm.bigIntEnabled) return t;
/* else fall through */
default:
return util.isBindableTypedArray(v) ? BindTypes.blob : undefined;
}
};
/**
If isSupportedBindType(v) returns a truthy value, this
function returns that value, else it throws.
*/
const affirmSupportedBindType = function(v){
//sqlite3.config.log('affirmSupportedBindType',v);
return isSupportedBindType(v) || toss3("Unsupported bind() argument type:",typeof v);
};
/**
If key is a number and within range of stmt's bound parameter
count, key is returned.
If key is not a number then it is checked against named
parameters. If a match is found, its index is returned.
Else it throws.
*/
const affirmParamIndex = function(stmt,key){
const n = ('number'===typeof key)
? key : capi.sqlite3_bind_parameter_index(stmt.pointer, key);
if(0===n || !util.isInt32(n)){
toss3("Invalid bind() parameter name: "+key);
}
else if(n<1 || n>stmt.parameterCount) toss3("Bind index",key,"is out of range.");
return n;
};
/**
If stmt._lockedByExec is truthy, this throws an exception
complaining that the 2nd argument (an operation name,
e.g. "bind()") is not legal while the statement is "locked".
Locking happens before an exec()-like callback is passed a
statement, to ensure that the callback does not mutate or
finalize the statement. If it does not throw, it returns stmt.
*/
const affirmNotLockedByExec = function(stmt,currentOpName){
if(stmt._lockedByExec){
toss3("Operation is illegal when statement is locked:",currentOpName);
}
return stmt;
};
/**
Binds a single bound parameter value on the given stmt at the
given index (numeric or named) using the given bindType (see
the BindTypes enum) and value. Throws on error. Returns stmt on
success.
*/
const bindOne = function f(stmt,ndx,bindType,val){
affirmNotLockedByExec(affirmStmtOpen(stmt), 'bind()');
if(!f._){
f._tooBigInt = (v)=>toss3(
"BigInt value is too big to store without precision loss:", v
);
f._ = {
string: function(stmt, ndx, val, asBlob){
const [pStr, n] = wasm.allocCString(val, true);
const f = asBlob ? capi.sqlite3_bind_blob : capi.sqlite3_bind_text;
return f(stmt.pointer, ndx, pStr, n, capi.SQLITE_WASM_DEALLOC);
}
};
}/* static init */
affirmSupportedBindType(val);
ndx = affirmParamIndex(stmt,ndx);
let rc = 0;
switch((null===val || undefined===val) ? BindTypes.null : bindType){
case BindTypes.null:
rc = capi.sqlite3_bind_null(stmt.pointer, ndx);
break;
case BindTypes.string:
rc = f._.string(stmt, ndx, val, false);
break;
case BindTypes.number: {
let m;
if(util.isInt32(val)) m = capi.sqlite3_bind_int;
else if('bigint'===typeof val){
if(!util.bigIntFits64(val)){
f._tooBigInt(val);
}else if(wasm.bigIntEnabled){
m = capi.sqlite3_bind_int64;
}else if(util.bigIntFitsDouble(val)){
val = Number(val);
m = capi.sqlite3_bind_double;
}else{
f._tooBigInt(val);
}
}else{ // !int32, !bigint
val = Number(val);
if(wasm.bigIntEnabled && Number.isInteger(val)){
m = capi.sqlite3_bind_int64;
}else{
m = capi.sqlite3_bind_double;
}
}
rc = m(stmt.pointer, ndx, val);
break;
}
case BindTypes.boolean:
rc = capi.sqlite3_bind_int(stmt.pointer, ndx, val ? 1 : 0);
break;
case BindTypes.blob: {
if('string'===typeof val){
rc = f._.string(stmt, ndx, val, true);
break;
}else if(val instanceof ArrayBuffer){
val = new Uint8Array(val);
}else if(!util.isBindableTypedArray(val)){
toss3("Binding a value as a blob requires",
"that it be a string, Uint8Array, Int8Array, or ArrayBuffer.");
}
const pBlob = wasm.alloc(val.byteLength || 1);
wasm.heap8().set(val.byteLength ? val : [0], pBlob)
rc = capi.sqlite3_bind_blob(stmt.pointer, ndx, pBlob, val.byteLength,
capi.SQLITE_WASM_DEALLOC);
break;
}
default:
sqlite3.config.warn("Unsupported bind() argument type:",val);
toss3("Unsupported bind() argument type: "+(typeof val));
}
if(rc) DB.checkRc(stmt.db.pointer, rc);
stmt._mayGet = false;
return stmt;
};
Stmt.prototype = {
/**
"Finalizes" this statement. This is a no-op if the statement
has already been finalized. Returns the result of
sqlite3_finalize() (0 on success, non-0 on error), or the
undefined value if the statement has already been
finalized. Regardless of success or failure, most methods in
this class will throw if called after this is.
This method always throws if called when it is illegal to do
so. Namely, when triggered via a per-row callback handler of a
DB.exec() call.
*/
finalize: function(){
if(this.pointer){
affirmNotLockedByExec(this,'finalize()');
const rc = capi.sqlite3_finalize(this.pointer);
delete __stmtMap.get(this.db)[this.pointer];
__ptrMap.delete(this);
delete this._mayGet;
delete this.parameterCount;
delete this._lockedByExec;
delete this.db;
return rc;
}
},
/**
Clears all bound values. Returns this object. Throws if this
statement has been finalized or if modification of the
statement is currently illegal (e.g. in the per-row callback of
a DB.exec() call).
*/
clearBindings: function(){
affirmNotLockedByExec(affirmStmtOpen(this), 'clearBindings()')
capi.sqlite3_clear_bindings(this.pointer);
this._mayGet = false;
return this;
},
/**
Resets this statement so that it may be step()ed again from the
beginning. Returns this object. Throws if this statement has
been finalized, if it may not legally be reset because it is
currently being used from a DB.exec() callback, or if the
underlying call to sqlite3_reset() returns non-0.
If passed a truthy argument then this.clearBindings() is
also called, otherwise any existing bindings, along with
any memory allocated for them, are retained.
In versions 3.42.0 and earlier, this function did not throw if
sqlite3_reset() returns non-0, but it was discovered that
throwing (or significant extra client-side code) is necessary
in order to avoid certain silent failure scenarios, as
discussed at:
https://sqlite.org/forum/forumpost/36f7a2e7494897df
*/
reset: function(alsoClearBinds){
affirmNotLockedByExec(this,'reset()');
if(alsoClearBinds) this.clearBindings();
const rc = capi.sqlite3_reset(affirmStmtOpen(this).pointer);
this._mayGet = false;
checkSqlite3Rc(this.db, rc);
return this;
},
/**
Binds one or more values to its bindable parameters. It
accepts 1 or 2 arguments:
If passed a single argument, it must be either an array, an
object, or a value of a bindable type (see below).
If passed 2 arguments, the first one is the 1-based bind
index or bindable parameter name and the second one must be
a value of a bindable type.
Bindable value types:
- null is bound as NULL.
- undefined as a standalone value is a no-op intended to
simplify certain client-side use cases: passing undefined as
a value to this function will not actually bind anything and
this function will skip confirmation that binding is even
legal. (Those semantics simplify certain client-side uses.)
Conversely, a value of undefined as an array or object
property when binding an array/object (see below) is treated
the same as null.
- Numbers are bound as either doubles or integers: doubles if
they are larger than 32 bits, else double or int32, depending
on whether they have a fractional part. Booleans are bound as
integer 0 or 1. It is not expected the distinction of binding
doubles which have no fractional parts is integers is
significant for the majority of clients due to sqlite3's data
typing model. If [BigInt] support is enabled then this
routine will bind BigInt values as 64-bit integers if they'll
fit in 64 bits. If that support disabled, it will store the
BigInt as an int32 or a double if it can do so without loss
of precision. If the BigInt is _too BigInt_ then it will
throw.
- Strings are bound as strings (use bindAsBlob() to force
blob binding).
- Uint8Array, Int8Array, and ArrayBuffer instances are bound as
blobs.
If passed an array, each element of the array is bound at
the parameter index equal to the array index plus 1
(because arrays are 0-based but binding is 1-based).
If passed an object, each object key is treated as a
bindable parameter name. The object keys _must_ match any
bindable parameter names, including any `$`, `@`, or `:`
prefix. Because `$` is a legal identifier chararacter in
JavaScript, that is the suggested prefix for bindable
parameters: `stmt.bind({$a: 1, $b: 2})`.
It returns this object on success and throws on
error. Errors include:
- Any bind index is out of range, a named bind parameter
does not match, or this statement has no bindable
parameters.
- Any value to bind is of an unsupported type.
- Passed no arguments or more than two.
- The statement has been finalized.
*/
bind: function(/*[ndx,] arg*/){
affirmStmtOpen(this);
let ndx, arg;
switch(arguments.length){
case 1: ndx = 1; arg = arguments[0]; break;
case 2: ndx = arguments[0]; arg = arguments[1]; break;
default: toss3("Invalid bind() arguments.");
}
if(undefined===arg){
/* It might seem intuitive to bind undefined as NULL
but this approach simplifies certain client-side
uses when passing on arguments between 2+ levels of
functions. */
return this;
}else if(!this.parameterCount){
toss3("This statement has no bindable parameters.");
}
this._mayGet = false;
if(null===arg){
/* bind NULL */
return bindOne(this, ndx, BindTypes.null, arg);
}
else if(Array.isArray(arg)){
/* bind each entry by index */
if(1!==arguments.length){
toss3("When binding an array, an index argument is not permitted.");
}
arg.forEach((v,i)=>bindOne(this, i+1, affirmSupportedBindType(v), v));
return this;
}else if(arg instanceof ArrayBuffer){
arg = new Uint8Array(arg);
}
if('object'===typeof arg/*null was checked above*/
&& !util.isBindableTypedArray(arg)){
/* Treat each property of arg as a named bound parameter. */
if(1!==arguments.length){
toss3("When binding an object, an index argument is not permitted.");
}
Object.keys(arg)
.forEach(k=>bindOne(this, k,
affirmSupportedBindType(arg[k]),
arg[k]));
return this;
}else{
return bindOne(this, ndx, affirmSupportedBindType(arg), arg);
}
toss3("Should not reach this point.");
},
/**
Special case of bind() which binds the given value using the
BLOB binding mechanism instead of the default selected one for
the value. The ndx may be a numbered or named bind index. The
value must be of type string, null/undefined (both get treated
as null), or a TypedArray of a type supported by the bind()
API. This API cannot bind numbers as blobs.
If passed a single argument, a bind index of 1 is assumed and
the first argument is the value.
*/
bindAsBlob: function(ndx,arg){
affirmStmtOpen(this);
if(1===arguments.length){
arg = ndx;
ndx = 1;
}
const t = affirmSupportedBindType(arg);
if(BindTypes.string !== t && BindTypes.blob !== t
&& BindTypes.null !== t){
toss3("Invalid value type for bindAsBlob()");
}
return bindOne(this, ndx, BindTypes.blob, arg);
},
/**
Steps the statement one time. If the result indicates that a
row of data is available, a truthy value is returned.
If no row of data is available, a falsy
value is returned. Throws on error.
*/
step: function(){
affirmNotLockedByExec(this, 'step()');
const rc = capi.sqlite3_step(affirmStmtOpen(this).pointer);
switch(rc){
case capi.SQLITE_DONE: return this._mayGet = false;
case capi.SQLITE_ROW: return this._mayGet = true;
default:
this._mayGet = false;
sqlite3.config.warn("sqlite3_step() rc=",rc,
capi.sqlite3_js_rc_str(rc),
"SQL =", capi.sqlite3_sql(this.pointer));
DB.checkRc(this.db.pointer, rc);
}
},
/**
Functions exactly like step() except that...
1) On success, it calls this.reset() and returns this object.
2) On error, it throws and does not call reset().
This is intended to simplify constructs like:
```
for(...) {
stmt.bind(...).stepReset();
}
```
Note that the reset() call makes it illegal to call this.get()
after the step.
*/
stepReset: function(){
this.step();
return this.reset();
},
/**
Functions like step() except that it calls finalize() on this
statement immediately after stepping, even if the step() call
throws.
On success, it returns true if the step indicated that a row of
data was available, else it returns false.
This is intended to simplify use cases such as:
```
aDb.prepare("insert into foo(a) values(?)").bind(123).stepFinalize();
```
*/
stepFinalize: function(){
try{
const rc = this.step();
this.reset(/*for INSERT...RETURNING locking case*/);
return rc;
}finally{
try{this.finalize()}
catch(e){/*ignored*/}
}
},
/**
Fetches the value from the given 0-based column index of
the current data row, throwing if index is out of range.
Requires that step() has just returned a truthy value, else
an exception is thrown.
By default it will determine the data type of the result
automatically. If passed a second arugment, it must be one
of the enumeration values for sqlite3 types, which are
defined as members of the sqlite3 module: SQLITE_INTEGER,
SQLITE_FLOAT, SQLITE_TEXT, SQLITE_BLOB. Any other value,
except for undefined, will trigger an exception. Passing
undefined is the same as not passing a value. It is legal
to, e.g., fetch an integer value as a string, in which case
sqlite3 will convert the value to a string.
If ndx is an array, this function behaves a differently: it
assigns the indexes of the array, from 0 to the number of
result columns, to the values of the corresponding column,
and returns that array.
If ndx is a plain object, this function behaves even
differentlier: it assigns the properties of the object to
the values of their corresponding result columns.
Blobs are returned as Uint8Array instances.
Potential TODO: add type ID SQLITE_JSON, which fetches the
result as a string and passes it (if it's not null) to
JSON.parse(), returning the result of that. Until then,
getJSON() can be used for that.
*/
get: function(ndx,asType){
if(!affirmStmtOpen(this)._mayGet){
toss3("Stmt.step() has not (recently) returned true.");
}
if(Array.isArray(ndx)){
let i = 0;
const n = this.columnCount;
while(i<n){
ndx[i] = this.get(i++);
}
return ndx;
}else if(ndx && 'object'===typeof ndx){
let i = 0;
const n = this.columnCount;
while(i<n){
ndx[capi.sqlite3_column_name(this.pointer,i)] = this.get(i++);
}
return ndx;
}
affirmColIndex(this, ndx);
switch(undefined===asType
? capi.sqlite3_column_type(this.pointer, ndx)
: asType){
case capi.SQLITE_NULL: return null;
case capi.SQLITE_INTEGER:{
if(wasm.bigIntEnabled){
const rc = capi.sqlite3_column_int64(this.pointer, ndx);
if(rc>=Number.MIN_SAFE_INTEGER && rc<=Number.MAX_SAFE_INTEGER){
/* Coerce "normal" number ranges to normal number values,
and only return BigInt-type values for numbers out of this
range. */
return Number(rc).valueOf();
}
return rc;
}else{
const rc = capi.sqlite3_column_double(this.pointer, ndx);
if(rc>Number.MAX_SAFE_INTEGER || rc<Number.MIN_SAFE_INTEGER){
/* Throwing here is arguable but, since we're explicitly
extracting an SQLITE_INTEGER-type value, it seems fair to throw
if the extracted number is out of range for that type.
This policy may be laxened to simply pass on the number and
hope for the best, as the C API would do. */
toss3("Integer is out of range for JS integer range: "+rc);
}
//sqlite3.config.log("get integer rc=",rc,isInt32(rc));
return util.isInt32(rc) ? (rc | 0) : rc;
}
}
case capi.SQLITE_FLOAT:
return capi.sqlite3_column_double(this.pointer, ndx);
case capi.SQLITE_TEXT:
return capi.sqlite3_column_text(this.pointer, ndx);
case capi.SQLITE_BLOB: {
const n = capi.sqlite3_column_bytes(this.pointer, ndx),
ptr = capi.sqlite3_column_blob(this.pointer, ndx),
rc = new Uint8Array(n);
//heap = n ? wasm.heap8() : false;
if(n) rc.set(wasm.heap8u().slice(ptr, ptr+n), 0);
//for(let i = 0; i < n; ++i) rc[i] = heap[ptr + i];
if(n && this.db._blobXfer instanceof Array){
/* This is an optimization soley for the
Worker-based API. These values will be
transfered to the main thread directly
instead of being copied. */
this.db._blobXfer.push(rc.buffer);
}
return rc;
}
default: toss3("Don't know how to translate",
"type of result column #"+ndx+".");
}
toss3("Not reached.");
},
/** Equivalent to get(ndx) but coerces the result to an
integer. */
getInt: function(ndx){return this.get(ndx,capi.SQLITE_INTEGER)},
/** Equivalent to get(ndx) but coerces the result to a
float. */
getFloat: function(ndx){return this.get(ndx,capi.SQLITE_FLOAT)},
/** Equivalent to get(ndx) but coerces the result to a
string. */
getString: function(ndx){return this.get(ndx,capi.SQLITE_TEXT)},
/** Equivalent to get(ndx) but coerces the result to a
Uint8Array. */
getBlob: function(ndx){return this.get(ndx,capi.SQLITE_BLOB)},
/**
A convenience wrapper around get() which fetches the value
as a string and then, if it is not null, passes it to
JSON.parse(), returning that result. Throws if parsing
fails. If the result is null, null is returned. An empty
string, on the other hand, will trigger an exception.
*/
getJSON: function(ndx){
const s = this.get(ndx, capi.SQLITE_STRING);
return null===s ? s : JSON.parse(s);
},
// Design note: the only reason most of these getters have a 'get'
// prefix is for consistency with getVALUE_TYPE(). The latter
// arguably really need that prefix for API readability and the
// rest arguably don't, but consistency is a powerful thing.
/**
Returns the result column name of the given index, or
throws if index is out of bounds or this statement has been
finalized. This can be used without having run step()
first.
*/
getColumnName: function(ndx){
return capi.sqlite3_column_name(
affirmColIndex(affirmStmtOpen(this),ndx).pointer, ndx
);
},
/**
If this statement potentially has result columns, this function
returns an array of all such names. If passed an array, it is
used as the target and all names are appended to it. Returns
the target array. Throws if this statement cannot have result
columns. This object's columnCount property holds the number of
columns.
*/
getColumnNames: function(tgt=[]){
affirmColIndex(affirmStmtOpen(this),0);
const n = this.columnCount;
for(let i = 0; i < n; ++i){
tgt.push(capi.sqlite3_column_name(this.pointer, i));
}
return tgt;
},
/**
If this statement has named bindable parameters and the
given name matches one, its 1-based bind index is
returned. If no match is found, 0 is returned. If it has no
bindable parameters, the undefined value is returned.
*/
getParamIndex: function(name){
return (affirmStmtOpen(this).parameterCount
? capi.sqlite3_bind_parameter_index(this.pointer, name)
: undefined);
}
}/*Stmt.prototype*/;
{/* Add the `pointer` property to DB and Stmt. */
const prop = {
enumerable: true,
get: function(){return __ptrMap.get(this)},
set: ()=>toss3("The pointer property is read-only.")
}
Object.defineProperty(Stmt.prototype, 'pointer', prop);
Object.defineProperty(DB.prototype, 'pointer', prop);
}
/**
Stmt.columnCount is an interceptor for sqlite3_column_count().
This requires an unfortunate performance hit compared to caching
columnCount when the Stmt is created/prepared (as was done in
SQLite <=3.42.0), but is necessary in order to handle certain
corner cases, as described in
https://sqlite.org/forum/forumpost/7774b773937cbe0a.
*/
Object.defineProperty(Stmt.prototype, 'columnCount', {
enumerable: false,
get: function(){return capi.sqlite3_column_count(this.pointer)},
set: ()=>toss3("The columnCount property is read-only.")
});
/** The OO API's public namespace. */
sqlite3.oo1 = {
DB,
Stmt
}/*oo1 object*/;
if(util.isUIThread()){
/**
Functionally equivalent to DB(storageName,'c','kvvfs') except
that it throws if the given storage name is not one of 'local'
or 'session'.
*/
sqlite3.oo1.JsStorageDb = function(storageName='session'){
if('session'!==storageName && 'local'!==storageName){
toss3("JsStorageDb db name must be one of 'session' or 'local'.");
}
dbCtorHelper.call(this, {
filename: storageName,
flags: 'c',
vfs: "kvvfs"
});
};
const jdb = sqlite3.oo1.JsStorageDb;
jdb.prototype = Object.create(DB.prototype);
/** Equivalent to sqlite3_js_kvvfs_clear(). */
jdb.clearStorage = capi.sqlite3_js_kvvfs_clear;
/**
Clears this database instance's storage or throws if this
instance has been closed. Returns the number of
database blocks which were cleaned up.
*/
jdb.prototype.clearStorage = function(){
return jdb.clearStorage(affirmDbOpen(this).filename);
};
/** Equivalent to sqlite3_js_kvvfs_size(). */
jdb.storageSize = capi.sqlite3_js_kvvfs_size;
/**
Returns the _approximate_ number of bytes this database takes
up in its storage or throws if this instance has been closed.
*/
jdb.prototype.storageSize = function(){
return jdb.storageSize(affirmDbOpen(this).filename);
};
}/*main-window-only bits*/
});
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