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Initial bits for a JS API variant in which the client operates in the main thread and sqlite3 in a Worker. This is far from complete.

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FossilOrigin-Name: f6d6f969791f0d2367ae5418623b4794f6df657d9d7d9002fb5aec4206dcfd4c
This commit is contained in:
stephan
2022-06-01 00:00:59 +00:00
parent c7fc08f69a
commit bff17db433
7 changed files with 164 additions and 16 deletions
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46
ext/fiddle/sqlite3-api.js
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@ -85,7 +85,8 @@
if(!Module.postRun) Module.postRun = [];
/* ^^^^ the name Module is, in this setup, scope-local in the generated
file sqlite3.js, with which this file gets combined at build-time. */
Module.postRun.push(function(namespace){
Module.postRun.push(function(namespace/*the module object, the target for
installed features*/){
'use strict';
/* For reference: sql.js does essentially everything we want and
it solves much of the wasm-related voodoo, but we'll need a
@ -470,7 +471,7 @@ Module.postRun.push(function(namespace){
execMulti():
- .multi: if true, this function acts as a proxy for
execMulti().
execMulti() and behaves identically to that function.
*/
exec: function(/*(sql [,optionsObj]) or (optionsObj)*/){
affirmDbOpen(this);
@ -549,13 +550,15 @@ Module.postRun.push(function(namespace){
ACHTUNG #1: The callback MUST NOT modify the Stmt
object. Calling any of the Stmt.get() variants,
Stmt.getColumnName(), or simililar, is legal, but calling
Stmt.getColumnName(), or similar, is legal, but calling
step() or finalize() is not. Routines which are illegal
in this context will trigger an exception.
ACHTUNG #2: The semantics of the `bind` and `callback`
options may well change or those options may be removed
altogether for this function (but retained for exec()).
Generally speaking, neither bind parameters nor a callback
are generically useful when executing multi-statement SQL.
*/
execMulti: function(/*(sql [,obj]) || (obj)*/){
affirmDbOpen(this);
@ -1327,8 +1330,8 @@ Module.postRun.push(function(namespace){
DB,
Stmt,
/**
Reports whether a given compile-time option, named by the
given argument. It has several distinct uses:
Reports info about compile-time options. It has several
distinct uses:
If optName is an array then it is expected to be a list of
compilation options and this function returns an object
@ -1387,10 +1390,41 @@ Module.postRun.push(function(namespace){
'string'===typeof optName
) ? !!api.sqlite3_compileoption_used(optName) : false;
}
};
}/*SQLite3 object*/;
namespace.sqlite3 = {
api: api,
SQLite3
};
if(self === self.window){
/* This is running in the main window thread, so we're done. */
return;
}
/******************************************************************
End of main window thread. What follows is only intended for use
in Worker threads.
******************************************************************/
/*
TODO: we need an API which can proxy the DB API via a Worker
message interface. The primary quirky factor in such an API is
that clients cannot pass callback functions to it, so have to receive
all query results via asynchronous message-passing.
Certain important considerations here include:
- Support only one db connectior or multiple? The former is far
easier, but there's always going to be a user out there who
wants to juggle six database handles at once.
- Fetching multiple results: do we pass them on as a series of
messages, with start/end messages on either end, or do we
collect all results and bundle them back in a single message?
The former is, generically speaking, more memory-efficient but
the latter far easier to implement in this environment.
*/
setTimeout(()=>postMessage({type:'sqlite3-api',data:'loaded'}), 0);
});

35
ext/fiddle/sqlite3-worker.js Normal file
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@ -0,0 +1,35 @@
/*
2022-05-23
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.
***********************************************************************
UNDER CONSTRUCTION
This is a JS Worker file for the main sqlite3 api. It loads
sqlite3.js and offers access to the db via the Worker
message-passing interface.
*/
"use strict";
(function(){
/** Posts a worker message as {type:type, data:data}. */
const wMsg = (type,data)=>self.postMessage({type, data});
self.onmessage = function(ev){
/*ev = ev.data;
switch(ev.type){
default: break;
};*/
console.warn("Unknown sqlite3-worker message type:",ev);
};
importScripts('sqlite3.js');
initSqlite3Module().then(function(){
wMsg('sqlite3-api','ready');
});
})();

3
ext/fiddle/testing1.js
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@ -10,7 +10,8 @@
***********************************************************************
A basic test script for sqlite3-api.js.
A basic test script for sqlite3-api.js. This file must be run in
main JS thread and sqlite3.js must have been loaded before it.
*/
(function(){
const T = self.SqliteTestUtil;

32
ext/fiddle/testing2.html Normal file
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@ -0,0 +1,32 @@
<!doctype html>
<html lang="en-us">
<head>
<meta charset="utf-8">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link rel="shortcut icon" href="data:image/x-icon;," type="image/x-icon">
<link rel="stylesheet" href="emscripten.css"/>
<link rel="stylesheet" href="testing.css"/>
<title>sqlite3-worker.js tests</title>
<style></style>
</head>
<body>
<header id='titlebar'><span>sqlite3-worker.js tests</span></header>
<!-- emscripten bits -->
<figure id="module-spinner">
<div class="spinner"></div>
<div class='center'><strong>Initializing app...</strong></div>
<div class='center'>
On a slow internet connection this may take a moment. If this
message displays for "a long time", intialization may have
failed and the JavaScript console may contain clues as to why.
</div>
</figure>
<div class="emscripten" id="module-status">Downloading...</div>
<div class="emscripten">
<progress value="0" max="100" id="module-progress" hidden='1'></progress>
</div><!-- /emscripten bits -->
<div>Everything on this page happens in the dev console.</div>
<script src="testing-common.js"></script>
<script src="testing2.js"></script>
</body>
</html>

43
ext/fiddle/testing2.js Normal file
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@ -0,0 +1,43 @@
/*
2022-05-22
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.
***********************************************************************
A basic test script for sqlite3-worker.js.
*/
(function(){
/** Posts a worker message as {type:type, data:data}. */
const SW = new Worker("sqlite3-worker.js");
const wMsg = (type,data)=>SW.postMessage({type, data});
const log = console.log.bind(console);
const warn = console.warn.bind(console);
SW.onmessage = function(ev){
if(!ev.data || 'object'!==typeof ev.data){
warn("Unknown sqlite3-worker message type:",ev);
return;
}
ev = ev.data/*expecting a nested object*/;
switch(ev.type){
case 'sqlite3-api':
switch(ev.data){
case 'loaded':
log("Message:",ev); return;
case 'ready':
log("Message:",ev);
self.sqlite3TestModule.setStatus(null);
return;
default: break;
}
break;
}
warn("Unknown sqlite3-api message type:",ev);
};
log("Init complete, but async bits may still be running.");
})();