Improved caching and reuse of JSON parses.

FossilOrigin-Name: df099ad713011b67b09cb1e5f0fa2e6b45f9cee0ce9d3c118c5dbca3563d20a5

manifest

@@ -1,5 +1,5 @@
-C Remove\sthe\sbatch\sSQL\srunner\sfrom\sthe\sJS\sbuild's\s'all'\starget,\sas\sit's\slong-since\sunused\sand\sadds\snoticable\sbuild\stime.\sAdd\smakefile\scomments\sabout\sJSPI.
-D 2023-07-26T11:41:41.032
+C Improved\scaching\sand\sreuse\sof\sJSON\sparses.
+D 2023-07-26T14:18:06.239
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -598,7 +598,7 @@ 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 46ea5566e1363f4f353db79b0378c2bf8ffdf9d4667daee3df67b14669767bed
+F src/json.c 512bc389b42c68b34571ca532afb0f4bb235b1fc11ea5c9a4f6850c64fa12ab4
 F src/legacy.c d7874bc885906868cd51e6c2156698f2754f02d9eee1bae2d687323c3ca8e5aa
 F src/loadext.c 176d6b2cb18a6ad73b133db17f6fc351c4d9a2d510deebdb76c22bde9cfd1465
 F src/main.c 512b1d45bc556edf4471a845afb7ba79e64bd5b832ab222dc195c469534cd002
@@ -634,7 +634,7 @@ F src/pcache1.c 602acb23c471bb8d557a6f0083cc2be641d6cafcafa19e481eba7ef4c9ca0f00
 F src/pragma.c 37b8fb02d090262280c86e1e2654bf59d8dbfbfe8dc6733f2b968a11374c095a
 F src/pragma.h e690a356c18e98414d2e870ea791c1be1545a714ba623719deb63f7f226d8bb7
 F src/prepare.c d6c4354f8ea0dc06962fbabc4b68c4471a45276a2918c929be00f9f537f69eb1
-F src/printf.c 84b7b4b647f336934a5ab2e7f0c52555833cc0778d2d60e016cca52ee8c6cd8f
+F src/printf.c e3ba080e2f409f9bfcc8d34724e6fc160e9c718dc92d0548f6b71b8b6f860ce2
 F src/random.c 606b00941a1d7dd09c381d3279a058d771f406c5213c9932bbd93d5587be4b9c
 F src/resolve.c 37953a5f36c60bea413c3c04efcd433b6177009f508ef2ace0494728912fe2e9
 F src/rowset.c 8432130e6c344b3401a8874c3cb49fefe6873fec593294de077afea2dce5ec97
@@ -643,7 +643,7 @@ F src/shell.c.in d320d8a13636de06d777cc1eab981caca304e175464e98183cf4ea68d93db81
 F src/sqlite.h.in f999ef3642f381d69679b2516b430dbcb6c5a2a951b7f5e43dc4751b474a5774
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h da473ce2b3d0ae407a6300c4a164589b9a6bfdbec9462688a8593ff16f3bb6e4
-F src/sqliteInt.h dcb1a885e8b6cb78df618944b89d44361a99d0fe33e1bba2c150a855f7dc5599
+F src/sqliteInt.h 30d7b0d586a4d03a384dcb60088c81b6fc6f74ce85cc3a0b3242eedc3cc24dbd
 F src/sqliteLimit.h 33b1c9baba578d34efe7dfdb43193b366111cdf41476b1e82699e14c11ee1fb6
 F src/status.c 160c445d7d28c984a0eae38c144f6419311ed3eace59b44ac6dafc20db4af749
 F src/table.c 0f141b58a16de7e2fbe81c308379e7279f4c6b50eb08efeec5892794a0ba30d1
@@ -714,7 +714,7 @@ F src/vdbeInt.h 401813862f9d75af01bdb2ab99253ad019e9d6ddcc8058e4fa61a43e9a60d1f7
 F src/vdbeapi.c dde6c4d0f87486f056b9db4d1ea185bb1d84a6839102b86e76316ba590d07cc7
 F src/vdbeaux.c b5e3f7e158518b4eca6f166ac43900640a3fe9735c710e12bfa119af21059339
 F src/vdbeblob.c 2516697b3ee8154eb8915f29466fb5d4f1ae39ee8b755ea909cefaf57ec5e2ce
-F src/vdbemem.c 40afb83ed848e235848ffdd3ba25adca4ba602111b8ed3b05ae3b1b12e0eacee
+F src/vdbemem.c 33da4f30ddba2670bc1e617c3262b66aef2a8039043d4ff93e5c97974991089d
 F src/vdbesort.c 0d40dca073c94e158ead752ef4225f4fee22dee84145e8c00ca2309afb489015
 F src/vdbetrace.c fe0bc29ebd4e02c8bc5c1945f1d2e6be5927ec12c06d89b03ef2a4def34bf823
 F src/vdbevtab.c aae4bd769410eb7e1d02c42613eec961d514459b1c3c1c63cfc84e92a137daac
@@ -1131,7 +1131,7 @@ F test/fuzzdata2.db 128b3feeb78918d075c9b14b48610145a0dd4c8d6f1ca7c2870c7e425f5b
 F test/fuzzdata3.db c6586d3e3cef0fbc18108f9bb649aa77bfc38aba
 F test/fuzzdata4.db b502c7d5498261715812dd8b3c2005bad08b3a26e6489414bd13926cd3e42ed2
 F test/fuzzdata5.db e35f64af17ec48926481cfaf3b3855e436bd40d1cfe2d59a9474cb4b748a52a5
-F test/fuzzdata6.db 92a80e4afc172c24f662a10a612d188fb272de4a9bd19e017927c95f737de6d7
+F test/fuzzdata6.db b8725a5f5cf7a3b7241a9038e57ca7e7cc8c3f4d86b44bd770617bda245ab2b0
 F test/fuzzdata7.db 0166b56fd7a6b9636a1d60ef0a060f86ddaecf99400a666bb6e5bbd7199ad1f2
 F test/fuzzdata8.db f6c2f2af4deaaae0ddb3310d509c2659990794aa653dc501b80a0534c3493f80
 F test/fuzzer1.test 3d4c4b7e547aba5e5511a2991e3e3d07166cfbb8
@@ -2044,8 +2044,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 72dc3f8c3255186ec412412b685b0b51ddcd08240f2353ac742fc7da8c23568e
-R 9fd280b1c194f8e5991f01cbec9ff41b
-U stephan
-Z 790924414d34e6bddbbcb85cdb1bbe6d
+P b8f708e35d4fa027d12089ac7c5589c36da5f68b98cf9792bb11276bf233a860 1bf85d4e388714a88f8940dcdec353c3e0267456697eff6963d34637912aecc9
+R 4ead394603f7f8681f2b78610f91baf6
+U drh
+Z 10059ebb7f758db6698db2e49096384a
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-b8f708e35d4fa027d12089ac7c5589c36da5f68b98cf9792bb11276bf233a860
+df099ad713011b67b09cb1e5f0fa2e6b45f9cee0ce9d3c118c5dbca3563d20a5

src/printf.c

@@ -1366,3 +1366,72 @@ void sqlite3_str_appendf(StrAccum *p, const char *zFormat, ...){
   sqlite3_str_vappendf(p, zFormat, ap);
   va_end(ap);
 }
+
+
+/*****************************************************************************
+** Reference counted string storage
+*****************************************************************************/
+
+/*
+** Increase the reference count of the string by one.
+**
+** The input parameter is returned.
+*/
+char *sqlite3RCStrRef(char *z){
+  RCStr *p = (RCStr*)z;
+  assert( p!=0 );
+  p--;
+  p->nRCRef++;
+  return z;
+}
+
+/*
+** Decrease the reference count by one.  Free the string when the
+** reference count reaches zero.
+*/
+void sqlite3RCStrUnref(char *z){
+  RCStr *p = (RCStr*)z;
+  assert( p!=0 );
+  p--;
+  assert( p->nRCRef>0 );
+  if( p->nRCRef>=2 ){
+    p->nRCRef--;
+  }else{
+    sqlite3_free(p);
+  }
+}
+
+/*
+** Create a new string that is capable of holding N bytes of text, not counting
+** the zero byte at the end.  The string is uninitialized.
+**
+** The reference count is initially 1.  Call sqlite3RCStrUnref() to free the
+** newly allocated string.
+**
+** This routine returns 0 on an OOM.
+*/
+char *sqlite3RCStrNew(u64 N){
+  RCStr *p = sqlite3_malloc64( N + sizeof(*p) + 1 );
+  if( p==0 ) return 0;
+  p->nRCRef = 1;
+  return (char*)&p[1];
+}
+
+/*
+** Change the size of the string so that it is able to hold N bytes.
+** The string might be reallocated, so return the new allocation.
+*/
+char *sqlite3RCStrResize(char *z, u64 N){
+  RCStr *p = (RCStr*)z;
+  RCStr *pNew;
+  assert( p!=0 );
+  p--;
+  assert( p->nRCRef==1 );
+  pNew = sqlite3_realloc64(p, N+sizeof(RCStr)+1);
+  if( pNew==0 ){
+    sqlite3_free(p);
+    return 0;
+  }else{
+    return (char*)&pNew[1];
+  }
+}

src/sqliteInt.h

@@ -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 +4062,25 @@ 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
+** differences:
+**
+**   1.  RCStr strings are reference counted.  They are deallocated
+**       when the reference count reaches zero.
+**
+**   2.  Use sqlite3RCStrUnref() to free an RCStr string rather than
+**       sqlite3_free()
+**
+**   3.  Make a (read-only) copy of a read-only RCStr string using
+**       sqlite3RCStrRef().
+*/
+struct RCStr {
+  u64 nRCRef;            /* Number of references */
+  /* Total structure size should be a multiple of 8 bytes for alignment */
+};
 
 /*
 ** A pointer to this structure is used to communicate information
@@ -5287,6 +5307,11 @@ void sqlite3OomClear(sqlite3*);
 int sqlite3ApiExit(sqlite3 *db, int);
 int sqlite3OpenTempDatabase(Parse *);
 
+char *sqlite3RCStrRef(char*);
+void sqlite3RCStrUnref(char*);
+char *sqlite3RCStrNew(u64);
+char *sqlite3RCStrResize(char*,u64);
+
 void sqlite3StrAccumInit(StrAccum*, sqlite3*, char*, int, int);
 int sqlite3StrAccumEnlarge(StrAccum*, i64);
 char *sqlite3StrAccumFinish(StrAccum*);

src/vdbemem.c

@@ -333,6 +333,11 @@ void sqlite3VdbeMemZeroTerminateIfAble(Mem *pMem){
       pMem->flags |= MEM_Term;
       return;
     }
+    if( pMem->xDel==(void(*)(void*))sqlite3RCStrUnref ){
+      /* Blindly assume that all RCStr objects are zero-terminated */
+      pMem->flags |= MEM_Term;
+      return;
+    }
   }else if( pMem->szMalloc>0 && pMem->szMalloc >= pMem->n+1 ){
     pMem->z[pMem->n] = 0;
     pMem->flags |= MEM_Term;