database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-11-11 01:42:22 +03:00
Code Activity

Create the new RCStr class of strings and try to use them for JSON storage.

Browse Source 
FossilOrigin-Name: c1b8725089bb3d006ec69add28f4fcb3f4e79412c7f438b5b1067c2227e77b9c
This commit is contained in:
drh
2023-07-25 15:08:18 +00:00
parent b715fe9d80
commit f02cc9a324
6 changed files with 258 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

52
src/sqliteInt.h
View File

@@ -1281,6 +1281,7 @@ typedef struct Parse Parse;
typedef struct ParseCleanup ParseCleanup;
typedef struct PreUpdate PreUpdate;
typedef struct PrintfArguments PrintfArguments;
typedef struct RCStr RCStr;
typedef struct RenameToken RenameToken;
typedef struct Returning Returning;
typedef struct RowSet RowSet;
@@ -4061,6 +4062,47 @@ struct sqlite3_str {
#define isMalloced(X) (((X)->printfFlags & SQLITE_PRINTF_MALLOCED)!=0)
/*
** The following object is the header for an "RCStr" or "reference-counted
** string". An RCStr is passed around and used like any other char*
** that has been dynamically allocated. The important interface
** difference is that it uses sqlite3RCStrUnref() as its destructor
** rather than sqlite3_free(). Other than that the two are interchangeable.
**
** Thus to return an RCStr object as the result of an SQL function use:
**
** sqlite3_result_text64(ctx,z,sz,sqlite3RCStrUnref,SQLITE_UTF8)
** ^^^^^^^^^^^^^^^^^
** Instead of sqlite3_free() or similar
**
** An SQL function can check its arguments to see if they are RCStr
** strings using the sqlite3ValueIsOfClass() function:
**
** sqlite3ValueIsOfClass(argv[i], sqlite3RCStrUnref);
**
** An RCStr string might be better than an ordinary string in some cases
** because:
**
** (1) You can duplicate it using sqlite3RCStrRef(x).
**
** (2) You can also add an associated object to the string. For
** example, if the string is JSON, perhaps the associated object
** is a parse of that JSON.
**
** Methods for an RCStr string begin with "sqlite3RCStr...".
*/
struct RCStr {
u32 nRCRef; /* Number of references */
#ifdef SQLITE_DEBUG
u32 uMagic; /* Magic number for sanity checking */
#endif
void *pAttach; /* Attachment to this string */
void (*xFree)(void*); /* Destructor for the attachment */
};
/* The Magic number used by RCStr for sanity checking. SQLITE_DEBUG only. */
#define SQLITE_RCSTR_MAGIC 0x3dc05d54
/*
** A pointer to this structure is used to communicate information
@@ -5180,6 +5222,7 @@ void sqlite3FileSuffix3(const char*, char*);
u8 sqlite3GetBoolean(const char *z,u8);
const void *sqlite3ValueText(sqlite3_value*, u8);
int sqlite3ValueIsOfClass(const sqlite3_value*, void(*)(void*));
int sqlite3ValueBytes(sqlite3_value*, u8);
void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,
void(*)(void*));
@@ -5287,6 +5330,15 @@ void sqlite3OomClear(sqlite3*);
int sqlite3ApiExit(sqlite3 *db, int);
int sqlite3OpenTempDatabase(Parse *);
char *sqlite3RCStrRef(char*);
void sqlite3RCStrUnref(char*);
char *sqlite3RCStrNew(u64);
u64 sqlite3RCStrSize(char*);
char *sqlite3RCStrResize(char*,u64);
int sqlite3RCStrIsWriteable(char*);
void sqlite3RCStrAttach(char*, void*, void(*)(void*));
void *sqlite3RCStrGetAttachment(char*,void(*)(void*));
void sqlite3StrAccumInit(StrAccum*, sqlite3*, char*, int, int);
int sqlite3StrAccumEnlarge(StrAccum*, i64);
char *sqlite3StrAccumFinish(StrAccum*);