diff options
| -rw-r--r-- | manifest | 16 | ||||
| -rw-r--r-- | manifest.uuid | 2 | ||||
| -rw-r--r-- | src/json.c | 267 | ||||
| -rw-r--r-- | src/printf.c | 2 | ||||
| -rw-r--r-- | src/sqliteInt.h | 3 |
5 files changed, 215 insertions, 75 deletions
@@ -1,5 +1,5 @@ -C Remove\sall\strace\sof\sJsonNode\sfrom\sthe\sJSON\simplementation.\s\sThe\sJSONB\sformat\nis\sused\sas\sthe\sinternal\sbinary\sencoding\sfor\ssearching\sand\sediting. -D 2023-11-30T23:36:14.577 +C First\sattempt\sto\sget\sthe\sJSON\stext-to-binary\scache\sworking.\s\sAll\stest\scases\npass,\sbut\sthe\scache\sseems\snot\sto\shelp\smuch. +D 2023-12-01T12:57:12.578 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724 @@ -688,7 +688,7 @@ F src/hash.h 3340ab6e1d13e725571d7cee6d3e3135f0779a7d8e76a9ce0a85971fa3953c51 F src/hwtime.h f9c2dfb84dce7acf95ce6d289e46f5f9d3d1afd328e53da8f8e9008e3b3caae6 F src/in-operator.md 10cd8f4bcd225a32518407c2fb2484089112fd71 F src/insert.c 3f0a94082d978bbdd33c38fefea15346c6c6bffb70bc645a71dc0f1f87dd3276 -F src/json.c c4f3602115334c210fbcdfb9565ba9fd322d29f7327b598fc0dd5dea4cb1b068 +F src/json.c 9a96faf916f572deb94b6cc7673ba6e299c48d153c18218e104a2c6ae37c2c8e F src/legacy.c d7874bc885906868cd51e6c2156698f2754f02d9eee1bae2d687323c3ca8e5aa F src/loadext.c 7432c944ff197046d67a1207790a1b13eec4548c85a9457eb0896bb3641dfb36 F src/main.c 1b89f3de98d1b59fec5bac1d66d6ece21f703821b8eaa0d53d9604c35309f6f9 @@ -724,7 +724,7 @@ F src/pcache1.c 602acb23c471bb8d557a6f0083cc2be641d6cafcafa19e481eba7ef4c9ca0f00 F src/pragma.c b5b4cff830575e6188cd56a295a57448d2b9dbc53f0dae58e22b97354cda3781 F src/pragma.h e690a356c18e98414d2e870ea791c1be1545a714ba623719deb63f7f226d8bb7 F src/prepare.c 371f6115cb69286ebc12c6f2d7511279c2e47d9f54f475d46a554d687a3b312c -F src/printf.c 9da63b9ae1c14789bcae12840f5d800fd9302500cd2d62733fac77f0041b4750 +F src/printf.c 18fbdf028345c8fbe6044f5f5bfda5a10d48d6287afef088cc21b0ca57985640 F src/random.c 606b00941a1d7dd09c381d3279a058d771f406c5213c9932bbd93d5587be4b9c F src/resolve.c d017bad7ba8e778617701a0e986fdeb393d67d6afa84fb28ef4e8b8ad2acf916 F src/rowset.c 8432130e6c344b3401a8874c3cb49fefe6873fec593294de077afea2dce5ec97 @@ -733,7 +733,7 @@ F src/shell.c.in 7bb83293775e1a5586d65212997442bc7acc70a2f1b781745da64ec3c2e4ea9 F src/sqlite.h.in d93a4821d2f792467a60f7dc81268d1bb8634f40c31694ef254cab4f9921f96a F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8 F src/sqlite3ext.h 3f046c04ea3595d6bfda99b781926b17e672fd6d27da2ba6d8d8fc39981dcb54 -F src/sqliteInt.h 6b82eb99a9d2887e873fb29e56befb7c50cf4624df615d23a28f071dc8abf5f6 +F src/sqliteInt.h aab66d149269f15f6f1011081b389f001f00b84045c69a4f9ec96dd68cc3a7d7 F src/sqliteLimit.h 33b1c9baba578d34efe7dfdb43193b366111cdf41476b1e82699e14c11ee1fb6 F src/status.c 160c445d7d28c984a0eae38c144f6419311ed3eace59b44ac6dafc20db4af749 F src/table.c 0f141b58a16de7e2fbe81c308379e7279f4c6b50eb08efeec5892794a0ba30d1 @@ -2145,8 +2145,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0 -P 7b5756fa6d00b093bf083a8d7a5ef5485f7a09e4eac473785c8380688f861a1b -R 38620fda20feff15c621a1f3bd3d0184 +P 11ebb5f712cc7a515e2e0f2be8c1d71de20c97fe5b74c4f4d72c84fd21182d35 +R 18f6bb3dc7a73112aa5c773b9941447e U drh -Z 66786c8d6e89beb8e06f2e4708cb9069 +Z 9a005b4c0b238db6966807971445cc41 # Remove this line to create a well-formed Fossil manifest. diff --git a/manifest.uuid b/manifest.uuid index be5cc905b..298549f7a 100644 --- a/manifest.uuid +++ b/manifest.uuid @@ -1 +1 @@ -11ebb5f712cc7a515e2e0f2be8c1d71de20c97fe5b74c4f4d72c84fd21182d35
\ No newline at end of file +25ed295f300fea6185104a73721076bccd2b2a6e411c78564266fa6dca4ff70c
\ No newline at end of file diff --git a/src/json.c b/src/json.c index 713dc76da..44fa5bf0b 100644 --- a/src/json.c +++ b/src/json.c @@ -165,7 +165,7 @@ static const char jsonIsSpace[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }; -#define fast_isspace(x) (jsonIsSpace[(unsigned char)x]) +#define jsonIsspace(x) (jsonIsSpace[(unsigned char)x]) /* ** Characters that are special to JSON. Control charaters, @@ -200,9 +200,35 @@ static const char jsonIsOk[256] = { #endif /* Objects */ +typedef struct JsonCache JsonCache; +typedef struct JsonCacheLine JsonCacheLine; typedef struct JsonString JsonString; typedef struct JsonParse JsonParse; + +/* +** Magic number used for the JSON parse cache in sqlite3_get_auxdata() +*/ +#define JSON_CACHE_ID (-429938) /* Cache entry */ +#define JSON_CACHE_SIZE 4 /* Max number of cache entries */ + +/* A cache mapping JSON text into JSONB blobs. +** +** All content, both JSON text and the JSONB blobs, is stored as RCStr +** objects. +*/ +struct JsonCacheLine { + u32 nJson; /* Size of the JSON text, in bytes */ + u32 nBlob; /* Size of the corresponding JSONB, in bytes */ + char *zJson; /* RCStr holding the JSON text */ + char *aBlob; /* RCStr holding the corresponding JSONB */ +}; +struct JsonCache { + sqlite3 *db; /* Database connection */ + int nUsed; /* Number of active entries in the cache */ + JsonCacheLine a[JSON_CACHE_SIZE]; /* One line for each cache entry */ +}; + /* An instance of this object represents a JSON string ** under construction. Really, this is a generic string accumulator ** that can be and is used to create strings other than JSON. @@ -258,11 +284,11 @@ struct JsonParse { u8 *aBlob; /* JSONB representation of JSON value */ u32 nBlob; /* Bytes of aBlob[] actually used */ u32 nBlobAlloc; /* Bytes allocated to aBlob[]. 0 if aBlob is external */ - char *zJson; /* Original JSON string (before edits) */ + char *zJson; /* Json text used for parsing */ u16 iDepth; /* Nesting depth */ u8 nErr; /* Number of errors seen */ u8 oom; /* Set to true if out of memory */ - u8 bJsonIsRCStr; /* True if zJson is an RCStr */ + u8 bBlobIsRCStr; /* True if aBlob is an RCStr */ u8 hasNonstd; /* True if input uses non-standard features like JSON5 */ u32 nJPRef; /* Number of references to this object */ int nJson; /* Length of the zJson string in bytes */ @@ -304,6 +330,113 @@ static int jsonFuncArgMightBeBinary(sqlite3_value *pJson); static u32 jsonXlateBlobToText(const JsonParse*,u32,JsonString*); static void jsonReturnParse(sqlite3_context*,JsonParse*); static JsonParse *jsonParseFuncArg(sqlite3_context*,sqlite3_value*,u32); +/************************************************************************** +** Utility routines for dealing with JsonCache objects +**************************************************************************/ + +/* +** Free a JsonCache object. +*/ +static void jsonCacheDelete(JsonCache *p){ + int i; + for(i=0; i<p->nUsed; i++){ + sqlite3RCStrUnref(p->a[i].zJson); + sqlite3RCStrUnref(p->a[i].aBlob); + } + sqlite3DbFree(p->db, p); +} +static void jsonCacheDeleteGeneric(void *p){ + jsonCacheDelete((JsonCache*)p); +} + +/* +** Insert a new entry into the cache. If the cache is full, expell +** the least recently used entry. Return SQLITE_OK on success or a +** result code otherwise. +** +** Both the input JSON and JSONB must be RCStr objects. +*/ +static int jsonCacheInsert( + sqlite3_context *ctx, /* The SQL statement context holding the cache */ + char *zJson, /* The key. Must be an RCStr! */ + u32 nJson, /* Number of bytes in zJson */ + char *aBlob, /* The value. Not an RCStr */ + u32 nBlob /* Number of bytes in aBlob */ +){ + JsonCache *p; + char *aRCBlob = 0; + + p = sqlite3_get_auxdata(ctx, JSON_CACHE_ID); + if( p==0 ){ + sqlite3 *db = sqlite3_context_db_handle(ctx); + p = sqlite3DbMallocZero(db, sizeof(*p)); + if( p==0 ) return SQLITE_NOMEM; + p->db = db; + sqlite3_set_auxdata(ctx, JSON_CACHE_ID, p, jsonCacheDeleteGeneric); + p = sqlite3_get_auxdata(ctx, JSON_CACHE_ID); + if( p==0 ) return SQLITE_NOMEM; + } + aRCBlob = sqlite3RCStrNew( nBlob ); + if( aRCBlob==0 ) return SQLITE_NOMEM; + memcpy(aRCBlob, aBlob, nBlob); + if( p->nUsed >= JSON_CACHE_SIZE ){ + sqlite3RCStrUnref(p->a[0].zJson); + sqlite3RCStrUnref(p->a[0].aBlob); + memmove(p->a, &p->a[1], (JSON_CACHE_SIZE-1)*sizeof(p->a[0])); + p->nUsed = JSON_CACHE_SIZE-1; + } + p->a[p->nUsed].nJson = nJson; + p->a[p->nUsed].nBlob = nBlob; + p->a[p->nUsed].zJson = sqlite3RCStrRef(zJson); + p->a[p->nUsed].aBlob = aRCBlob; + p->nUsed++; + return SQLITE_OK; +} + +/* +** Search for a cached translation of zJson (size: nJson bytes) into +** JSONB. Return it if found. +** +** The returned value is an RCStr object if it is not NULL. +** The caller is responsible for incrementing the reference count. +*/ +static u8 *jsonCacheSearch( + sqlite3_context *ctx, /* The SQL statement context holding the cache */ + char *zJson, /* The key. Might or might not be an RCStr */ + u32 nJson, /* Size of the key in bytes */ + u32 *pnBlob /* OUT: Size of the result in bytes */ +){ + JsonCache *p; + int i; + + assert( pnBlob!=0 ); + p = sqlite3_get_auxdata(ctx, JSON_CACHE_ID); + if( p==0 ){ + *pnBlob = 0; + return 0; + } + for(i=0; i<p->nUsed; i++){ + if( p->a[i].zJson==zJson ) break; + } + if( i>=p->nUsed ){ + for(i=0; i<p->nUsed; i++){ + if( p->a[i].nJson!=nJson ) continue; + if( memcmp(p->a[i].zJson, zJson, nJson)==0 ) break; + } + } + if( i<p->nUsed ){ + if( i<p->nUsed-1 ){ + JsonCacheLine tmp = p->a[i]; + memmove(&p->a[i], &p->a[i+1], (p->nUsed-i-1)*sizeof(tmp)); + p->a[p->nUsed-1] = tmp; + } + *pnBlob = p->a[i].nBlob; + return (u8*)p->a[i].aBlob; + }else{ + *pnBlob = 0; + return 0; + } +} /************************************************************************** ** Utility routines for dealing with JsonString objects @@ -569,8 +702,18 @@ static void jsonAppendSqlValue( ** the result of the SQL function. ** ** The JsonString is reset. +** +** If pParse and ctx are both non-NULL and if pParse->aBlob is valid +** then an attempt is made to cache the translation from JSON text into +** the blob. */ -static void jsonReturnString(JsonString *p){ +static void jsonReturnString( + JsonString *p, /* String to return */ + JsonParse *pParse, /* JSONB source or NULL */ + sqlite3_context *ctx /* Where to cache */ +){ + assert( (pParse!=0)==(ctx!=0) ); + assert( ctx==0 || ctx==p->pCtx ); if( p->eErr==0 ){ int flags = SQLITE_PTR_TO_INT(sqlite3_user_data(p->pCtx)); if( flags & JSON_BLOB ){ @@ -580,6 +723,16 @@ static void jsonReturnString(JsonString *p){ SQLITE_TRANSIENT, SQLITE_UTF8); }else if( jsonForceRCStr(p) ){ sqlite3RCStrRef(p->zBuf); + if( pParse ){ + int rc = jsonCacheInsert(ctx, p->zBuf, p->nUsed, + (char*)pParse->aBlob, pParse->nBlob); + if( rc==SQLITE_NOMEM ){ + sqlite3RCStrUnref(p->zBuf); + sqlite3_result_error_nomem(ctx); + jsonStringReset(p); + return; + } + } sqlite3_result_text64(p->pCtx, p->zBuf, p->nUsed, sqlite3RCStrUnref, SQLITE_UTF8); @@ -604,10 +757,12 @@ static void jsonReturnString(JsonString *p){ */ static void jsonParseReset(JsonParse *pParse){ assert( pParse->nJPRef<=1 ); - if( pParse->bJsonIsRCStr ){ - sqlite3RCStrUnref(pParse->zJson); - pParse->zJson = 0; - pParse->bJsonIsRCStr = 0; + if( pParse->bBlobIsRCStr ){ + assert( pParse->nBlobAlloc==0 ); + sqlite3RCStrUnref((char*)pParse->aBlob); + pParse->aBlob = 0; + pParse->nBlob = 0; + pParse->bBlobIsRCStr = 0; } if( pParse->nBlobAlloc ){ sqlite3_free(pParse->aBlob); @@ -637,46 +792,18 @@ static void jsonParseFree(JsonParse *pParse){ } /* -** Translate a single byte of Hex into an integer. -** This routine only works if h really is a valid hexadecimal -** character: 0..9a..fA..F -*/ -static u8 jsonHexToInt(int h){ - if( !sqlite3Isxdigit(h) ) return 0; -#ifdef SQLITE_EBCDIC - h += 9*(1&~(h>>4)); -#else - h += 9*(1&(h>>6)); -#endif - return (u8)(h & 0xf); -} - -/* ** Convert a 4-byte hex string into an integer */ static u32 jsonHexToInt4(const char *z){ u32 v; - v = (jsonHexToInt(z[0])<<12) - + (jsonHexToInt(z[1])<<8) - + (jsonHexToInt(z[2])<<4) - + jsonHexToInt(z[3]); + v = (sqlite3HexToInt(z[0])<<12) + + (sqlite3HexToInt(z[1])<<8) + + (sqlite3HexToInt(z[2])<<4) + + sqlite3HexToInt(z[3]); return v; } /* -** A macro to hint to the compiler that a function should not be -** inlined. -*/ -#if defined(__GNUC__) -# define JSON_NOINLINE __attribute__((noinline)) -#elif defined(_MSC_VER) && _MSC_VER>=1310 -# define JSON_NOINLINE __declspec(noinline) -#else -# define JSON_NOINLINE -#endif - - -/* ** Return true if z[] begins with 2 (or more) hexadecimal digits */ static int jsonIs2Hex(const char *z){ @@ -836,12 +963,6 @@ static const struct NanInfName { { 's', 'S', 4, JSONB_NULL, 4, "SNaN", "null" }, }; -/* -** Magic number used for the JSON parse cache in sqlite3_get_auxdata() -*/ -#define JSON_CACHE_ID (-429938) /* First cache entry */ -#define JSON_CACHE_SZ 4 /* Max number of cache entries */ - /* ** Compute the text of an error in JSON path syntax. @@ -1147,8 +1268,8 @@ json_parse_restart: if( z[j]==':' ){ j++; }else{ - if( fast_isspace(z[j]) ){ - do{ j++; }while( fast_isspace(z[j]) ); + if( jsonIsspace(z[j]) ){ + do{ j++; }while( jsonIsspace(z[j]) ); if( z[j]==':' ){ j++; goto parse_object_value; @@ -1173,8 +1294,8 @@ json_parse_restart: }else if( z[j]=='}' ){ break; }else{ - if( fast_isspace(z[j]) ){ - do{ j++; }while( fast_isspace(z[j]) ); + if( jsonIsspace(z[j]) ){ + do{ j++; }while( jsonIsspace(z[j]) ); if( z[j]==',' ){ continue; }else if( z[j]=='}' ){ @@ -1225,8 +1346,8 @@ json_parse_restart: }else if( z[j]==']' ){ break; }else{ - if( fast_isspace(z[j]) ){ - do{ j++; }while( fast_isspace(z[j]) ); + if( jsonIsspace(z[j]) ){ + do{ j++; }while( jsonIsspace(z[j]) ); if( z[j]==',' ){ continue; }else if( z[j]==']' ){ @@ -1488,7 +1609,7 @@ json_parse_restart: case 0x20: { do{ i++; - }while( fast_isspace(z[i]) ); + }while( jsonIsspace(z[i]) ); goto json_parse_restart; } case 0x0b: @@ -1560,7 +1681,7 @@ static int jsonConvertTextToBlob( if( pParse->oom ) i = -1; if( i>0 ){ assert( pParse->iDepth==0 ); - while( fast_isspace(zJson[i]) ) i++; + while( jsonIsspace(zJson[i]) ) i++; if( zJson[i] ){ i += json5Whitespace(&zJson[i]); if( zJson[i] ){ @@ -2197,7 +2318,7 @@ static void jsonReturnTextJsonFromBlob( x.nBlob = nBlob; jsonStringInit(&s, ctx); jsonXlateBlobToText(&x, 0, &s); - jsonReturnString(&s); + jsonReturnString(&s, 0, 0); } @@ -2338,7 +2459,7 @@ static void jsonReturnFromBlob( }else if( c=='0' ){ c = 0; }else if( c=='x' ){ - c = (jsonHexToInt(z[iIn+1])<<4) | jsonHexToInt(z[iIn+2]); + c = (sqlite3HexToInt(z[iIn+1])<<4) | sqlite3HexToInt(z[iIn+2]); iIn += 2; }else if( c=='\r' && z[i+1]=='\n' ){ iIn++; @@ -2455,7 +2576,7 @@ static int jsonFunctionArgToBlob( } /* -** Generate a bad path error for json_extract() +** Generate a bad path error. */ static void jsonBadPathError( sqlite3_context *ctx, /* The function call containing the error */ @@ -2599,6 +2720,22 @@ static JsonParse *jsonParseFuncArg( p->nJson = sqlite3_value_bytes(pArg); if( p->nJson==0 ) goto json_pfa_malformed; if( p->zJson==0 ) goto json_pfa_oom; + + p->aBlob = jsonCacheSearch(ctx, p->zJson, p->nJson, &p->nBlob); + if( p->aBlob ){ + if( flgs & JSON_EDITABLE ){ + u8 *pNew = sqlite3_malloc64( p->nBlob ); + if( pNew==0 ) goto json_pfa_oom; + memcpy(pNew, p->aBlob, p->nBlob); + p->aBlob = pNew; + p->nBlobAlloc = p->nBlob; + }else{ + sqlite3RCStrRef((char*)p->aBlob); + p->bBlobIsRCStr = 1; + } + return p; + } + if( flgs & JSON_KEEPERROR ) ctx = 0; if( jsonConvertTextToBlob(p, ctx) ){ if( flgs & JSON_KEEPERROR ){ @@ -2650,7 +2787,7 @@ static void jsonReturnParse( JsonString s; jsonStringInit(&s, ctx); jsonXlateBlobToText(p, 0, &s); - jsonReturnString(&s); + jsonReturnString(&s, p, ctx); sqlite3_result_subtype(ctx, JSON_SUBTYPE); } } @@ -2890,7 +3027,7 @@ static void jsonQuoteFunc( jsonStringInit(&jx, ctx); jsonAppendSqlValue(&jx, argv[0]); - jsonReturnString(&jx); + jsonReturnString(&jx, 0, 0); sqlite3_result_subtype(ctx, JSON_SUBTYPE); } @@ -2914,7 +3051,7 @@ static void jsonArrayFunc( jsonAppendSqlValue(&jx, argv[i]); } jsonAppendChar(&jx, ']'); - jsonReturnString(&jx); + jsonReturnString(&jx, 0, 0); sqlite3_result_subtype(ctx, JSON_SUBTYPE); } @@ -3058,7 +3195,7 @@ static void jsonExtractFunc( if( flags & JSON_JSON ){ jsonStringInit(&jx, ctx); jsonXlateBlobToText(p, j, &jx); - jsonReturnString(&jx); + jsonReturnString(&jx, 0, 0); jsonStringReset(&jx); assert( (flags & JSON_BLOB)==0 ); sqlite3_result_subtype(ctx, JSON_SUBTYPE); @@ -3091,7 +3228,7 @@ static void jsonExtractFunc( } if( argc>2 ){ jsonAppendChar(&jx, ']'); - jsonReturnString(&jx); + jsonReturnString(&jx, 0, 0); if( (flags & JSON_BLOB)==0 ){ sqlite3_result_subtype(ctx, JSON_SUBTYPE); } @@ -3389,7 +3526,7 @@ static void jsonObjectFunc( jsonAppendSqlValue(&jx, argv[i+1]); } jsonAppendChar(&jx, '}'); - jsonReturnString(&jx); + jsonReturnString(&jx, 0, 0); sqlite3_result_subtype(ctx, JSON_SUBTYPE); } @@ -3767,7 +3904,7 @@ static void jsonArrayCompute(sqlite3_context *ctx, int isFinal){ jsonAppendChar(pStr, ']'); flags = SQLITE_PTR_TO_INT(sqlite3_user_data(ctx)); if( pStr->eErr ){ - jsonReturnString(pStr); + jsonReturnString(pStr, 0, 0); return; }else if( flags & JSON_BLOB ){ jsonReturnStringAsBlob(pStr); @@ -3887,7 +4024,7 @@ static void jsonObjectCompute(sqlite3_context *ctx, int isFinal){ pStr->pCtx = ctx; flags = SQLITE_PTR_TO_INT(sqlite3_user_data(ctx)); if( pStr->eErr ){ - jsonReturnString(pStr); + jsonReturnString(pStr, 0, 0); return; }else if( flags & JSON_BLOB ){ jsonReturnStringAsBlob(pStr); diff --git a/src/printf.c b/src/printf.c index 3c0b182d3..c6b3803ca 100644 --- a/src/printf.c +++ b/src/printf.c @@ -1369,7 +1369,7 @@ void sqlite3_str_appendf(StrAccum *p, const char *zFormat, ...){ /***************************************************************************** -** Reference counted string storage +** Reference counted string/blob storage *****************************************************************************/ /* diff --git a/src/sqliteInt.h b/src/sqliteInt.h index 9e57354db..c7ced8699 100644 --- a/src/sqliteInt.h +++ b/src/sqliteInt.h @@ -4116,6 +4116,9 @@ struct sqlite3_str { ** ** 3. Make a (read-only) copy of a read-only RCStr string using ** sqlite3RCStrRef(). +** +** "String" is in the name, but an RCStr object can also be used to hold +** binary data. */ struct RCStr { u64 nRCRef; /* Number of references */ |