Performance optimization for JSON rendering logic.

FossilOrigin-Name: ea0b9aecbaca9a8e784fd2bcb50f78cbdcf4c5cfb45a7700bb222e4cc104c644

diff --git a/manifest b/manifest
index dbf0099f2da329007131d106a5f7d766510e260b..bd8750b7dcfa1e5e01e45e8f788b30f70140acb2 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Remove\san\sunreachable\sbranch\sin\sthe\sascii-to-floating-point\sconversion\sthat\nwas\sadded\sby\s[e989a37ff9d5b52e].
-D 2023-08-02T13:45:16.075
+C Performance\soptimization\sfor\sJSON\srendering\slogic.
+D 2023-08-02T16:06:02.660
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -603,7 +603,7 @@ 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 0bcc2e033821feb3048b8434ade2b7d22267005a0990656f4ef4ee25b4ac47bc
+F src/json.c cea55234b99879a6c3be04cd01f32e83f760672356415b541929cdd16441ede3
 F src/legacy.c d7874bc885906868cd51e6c2156698f2754f02d9eee1bae2d687323c3ca8e5aa
 F src/loadext.c 176d6b2cb18a6ad73b133db17f6fc351c4d9a2d510deebdb76c22bde9cfd1465
 F src/main.c 512b1d45bc556edf4471a845afb7ba79e64bd5b832ab222dc195c469534cd002
@@ -2049,8 +2049,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 354425f8d97437bd156265a6914f98cce91b42abc9e773453ef4d817e308dc9a
-R aa07c6b217b53d8658b8a233cbb6460f
+P c4347e4400e96f932ac12f8f22484a2ebce2a578d1b2181977954c432f117bfd
+R a3168d15b44149a629121fdff1d59acd
 U drh
-Z 99babb0a241aaf0b9de5cc7fdf7d857c
+Z 37bd268b83df81194e3e4e7be36a0655
 # Remove this line to create a well-formed Fossil manifest.

diff --git a/manifest.uuid b/manifest.uuid
index c2f1f3626d75cec69447c5e73ff4f34cee5fd9c1..ca5b942d1b9988ae4bde44965c100c365d85dfa0 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-c4347e4400e96f932ac12f8f22484a2ebce2a578d1b2181977954c432f117bfd
\ No newline at end of file
+ea0b9aecbaca9a8e784fd2bcb50f78cbdcf4c5cfb45a7700bb222e4cc104c644
\ No newline at end of file

diff --git a/src/json.c b/src/json.c
index 2a002ba087a49fd194239f5b29b01f5fabf5d150..5038fd3c46cc29cc61434d23bb56364caa670426 100644 (file)
--- a/src/json.c
+++ b/src/json.c
@@ -30,25 +30,51 @@
 ** increase for the parser.  (Ubuntu14.10 gcc 4.8.4 x64 with -Os).
 */
 static const char jsonIsSpace[] = {
-  0, 0, 0, 0, 0, 0, 0, 0,     0, 1, 1, 0, 0, 1, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
-  1, 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, 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, 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, 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, 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, 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, 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, 0, 0, 0, 0, 0, 0, 0,  0, 1, 1, 0, 0, 1, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,
+  1, 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, 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, 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, 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, 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, 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, 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])
 
+/*
+** Characters that are special to JSON.  Control charaters,
+** '"' and '\\'.
+*/
+static const char jsonIsOk[256] = {
+  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,
+  1, 1, 0, 1, 1, 1, 1, 0,  1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 0, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
+
+  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
+  1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1
+};
+
+
 #if !defined(SQLITE_DEBUG) && !defined(SQLITE_COVERAGE_TEST)
 #  define VVA(X)
 #else
@@ -357,11 +383,16 @@ static void jsonAppendString(JsonString *p, const char *zIn, u32 N){
   p->zBuf[p->nUsed++] = '"';
   for(i=0; i<N; i++){
     unsigned char c = ((unsigned const char*)zIn)[i];
-    if( c=='"' || c=='\\' ){
+    if( jsonIsOk[c] ){
+      p->zBuf[p->nUsed++] = c;
+    }else if( c=='"' || c=='\\' ){
       json_simple_escape:
       if( (p->nUsed+N+3-i > p->nAlloc) && jsonGrow(p,N+3-i)!=0 ) return;
       p->zBuf[p->nUsed++] = '\\';
-    }else if( c<=0x1f ){
+      p->zBuf[p->nUsed++] = c;
+    }else if( c=='\'' ){
+      p->zBuf[p->nUsed++] = c;
+    }else{
       static const char aSpecial[] = {
          0, 0, 0, 0, 0, 0, 0, 0, 'b', 't', 'n', 0, 'f', 'r', 0, 0,
          0, 0, 0, 0, 0, 0, 0, 0,   0,   0,   0, 0,   0,   0, 0, 0
@@ -372,6 +403,7 @@ static void jsonAppendString(JsonString *p, const char *zIn, u32 N){
       assert( aSpecial['\n']=='n' );
       assert( aSpecial['\r']=='r' );
       assert( aSpecial['\t']=='t' );
+      assert( c>=0 && c<sizeof(aSpecial) );
       if( aSpecial[c] ){
         c = aSpecial[c];
         goto json_simple_escape;
@@ -381,10 +413,9 @@ static void jsonAppendString(JsonString *p, const char *zIn, u32 N){
       p->zBuf[p->nUsed++] = 'u';
       p->zBuf[p->nUsed++] = '0';
       p->zBuf[p->nUsed++] = '0';
-      p->zBuf[p->nUsed++] = '0' + (c>>4);
-      c = "0123456789abcdef"[c&0xf];
+      p->zBuf[p->nUsed++] = "0123456789abcdef"[c>>4];
+      p->zBuf[p->nUsed++] = "0123456789abcdef"[c&0xf];
     }
-    p->zBuf[p->nUsed++] = c;
   }
   p->zBuf[p->nUsed++] = '"';
   assert( p->nUsed<p->nAlloc );
@@ -1465,26 +1496,7 @@ json_parse_restart:
   parse_string:
     cDelim = z[i];
     for(j=i+1; 1; j++){
-      static const char aOk[256] = {
-          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,
-          1, 1, 0, 1, 1, 1, 1, 0,  1, 1, 1, 1, 1, 1, 1, 1,
-          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
-          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
-          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 0, 1, 1, 1,
-          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
-          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
-
-          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
-          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
-          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
-          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
-          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
-          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
-          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
-          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
-      };
-      if( aOk[(unsigned char)z[j]] ) continue;
+      if( jsonIsOk[(unsigned char)z[j]] ) continue;
       c = z[j];
       if( c==cDelim ){
         break;