Take out the goofy '$$' path syntax. Instead, use subtypes to communicate when

a string is JSON.  Add the json() function that validates and minifies the
JSON and sets the appropriate subtype.

FossilOrigin-Name: 8a80d6459e246ec1b38325e1cbd1e862157138b3

1 files changed, 28 insertions, 61 deletions

diff --git a/ext/misc/json1.c b/ext/misc/json1.c
index 755d035c3..a217ce80b 100644
--- a/ext/misc/json1.c
+++ b/ext/misc/json1.c
@@ -68,6 +68,9 @@ struct JsonString {
 #define JSON_ARRAY    6
 #define JSON_OBJECT   7
 
+/* The "subtype" set for JSON values */
+#define JSON_SUBTYPE  74    /* Ascii for "J" */
+
 /*
 ** Names of the various JSON types:
 */
@@ -82,8 +85,7 @@ static const char * const jsonType[] = {
 #define JNODE_REMOVE  0x04         /* Do not output */
 #define JNODE_REPLACE 0x08         /* Replace with JsonNode.iVal */
 #define JNODE_APPEND  0x10         /* More ARRAY/OBJECT entries at u.iAppend */
-#define JNODE_JSON    0x20         /* Treat REPLACE as JSON text */
-#define JNODE_LABEL   0x40         /* Is a label of an object */
+#define JNODE_LABEL   0x20         /* Is a label of an object */
 
 
 /* A single node of parsed JSON
@@ -243,8 +245,7 @@ static void jsonAppendString(JsonString *p, const char *zIn, u32 N){
 */
 static void jsonAppendValue(
   JsonString *p,                 /* Append to this JSON string */
-  sqlite3_value *pValue,         /* Value to append */
-  u8 textIsJson                  /* Try to treat text values as JSON */
+  sqlite3_value *pValue          /* Value to append */
 ){
   switch( sqlite3_value_type(pValue) ){
     case SQLITE_NULL: {
@@ -261,7 +262,7 @@ static void jsonAppendValue(
     case SQLITE_TEXT: {
       const char *z = (const char*)sqlite3_value_text(pValue);
       u32 n = (u32)sqlite3_value_bytes(pValue);
-      if( textIsJson ){
+      if( sqlite3_value_subtype(pValue)==JSON_SUBTYPE ){
         jsonAppendRaw(p, z, n);
       }else{
         jsonAppendString(p, z, n);
@@ -365,8 +366,7 @@ static void jsonRenderNode(
           if( pNode[j].jnFlags & (JNODE_REMOVE|JNODE_REPLACE) ){
             if( pNode[j].jnFlags & JNODE_REPLACE ){
               jsonAppendSeparator(pOut);
-              jsonAppendValue(pOut, aReplace[pNode[j].iVal],
-                              (pNode[j].jnFlags & JNODE_JSON)!=0);
+              jsonAppendValue(pOut, aReplace[pNode[j].iVal]);
             }
           }else{
             jsonAppendSeparator(pOut);
@@ -391,8 +391,7 @@ static void jsonRenderNode(
             jsonRenderNode(&pNode[j], pOut, aReplace);
             jsonAppendChar(pOut, ':');
             if( pNode[j+1].jnFlags & JNODE_REPLACE ){
-              jsonAppendValue(pOut, aReplace[pNode[j+1].iVal],
-                              (pNode[j+1].jnFlags & JNODE_JSON)!=0);
+              jsonAppendValue(pOut, aReplace[pNode[j+1].iVal]);
             }else{
               jsonRenderNode(&pNode[j+1], pOut, aReplace);
             }
@@ -421,6 +420,7 @@ static void jsonReturnJson(
   jsonInit(&s, pCtx);
   jsonRenderNode(pNode, &s, aReplace);
   jsonResult(&s);
+  sqlite3_result_subtype(pCtx, JSON_SUBTYPE);
 }
 
 /*
@@ -951,21 +951,15 @@ static char *jsonPathSyntaxError(const char *zErr){
 **
 ** If pApnd!=NULL then try to append missing nodes and set *pApnd = 1 if
 ** nodes are appended.
-**
-** If the path starts with $$ then set *pFlags to JNODE_REPLACE|JNODE_JSON
-** as a single to the caller that the input text to be inserted should be 
-** interpreted as JSON rather than as ordinary text.
 */
 static JsonNode *jsonLookup(
   JsonParse *pParse,      /* The JSON to search */
   const char *zPath,      /* The path to search */
   int *pApnd,             /* Append nodes to complete path if not NULL */
-  sqlite3_context *pCtx,  /* Report errors here, if not NULL */
-  u8 *pFlags              /* Write JNODE_REPLACE or _REPLACE|_JSON here */
+  sqlite3_context *pCtx   /* Report errors here, if not NULL */
 ){
   const char *zErr = 0;
   JsonNode *pNode = 0;
-  u8 fg = JNODE_REPLACE;
 
   if( zPath==0 ) return 0;
   if( zPath[0]!='$' ){
@@ -973,15 +967,6 @@ static JsonNode *jsonLookup(
     goto lookup_err;
   }
   zPath++;
-  if( zPath[0]=='$' ){
-    if( pFlags==0 ){
-      zErr = zPath;
-      goto lookup_err;
-    }
-    zPath++;
-    fg = JNODE_REPLACE|JNODE_JSON;
-  }
-  if( pFlags ) *pFlags = fg;
   pNode = jsonLookupStep(pParse, 0, zPath, pApnd, &zErr);
   return pNode;
 
@@ -996,7 +981,6 @@ lookup_err:
       sqlite3_result_error_nomem(pCtx);
     }
   }
-  if( pFlags ) *pFlags = fg;
   return 0;
 }
 
@@ -1060,32 +1044,16 @@ static void jsonParseFunc(
 }
 
 /*
-** The json_test1(JSON) function parses and rebuilds the JSON string.
+** The json_test1(JSON) function return true (1) if the input is JSON
+** text generated by another json function.  It returns (0) if the input
+** is not known to be JSON.
 */
 static void jsonTest1Func(
   sqlite3_context *ctx,
   int argc,
   sqlite3_value **argv
 ){
-  JsonParse x;  /* The parse */
-  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
-  jsonReturnJson(x.aNode, ctx, 0);
-  jsonParseReset(&x);
-}
-
-/*
-** The json_nodecount(JSON) function returns the number of nodes in the
-** input JSON string.
-*/
-static void jsonNodeCountFunc(
-  sqlite3_context *ctx,
-  int argc,
-  sqlite3_value **argv
-){
-  JsonParse x;  /* The parse */
-  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
-  sqlite3_result_int64(ctx, (sqlite3_int64)x.nNode);
-  jsonParseReset(&x);
+  sqlite3_result_int(ctx, sqlite3_value_subtype(argv[0])==JSON_SUBTYPE);
 }
 #endif /* SQLITE_DEBUG */
 
@@ -1110,10 +1078,11 @@ static void jsonArrayFunc(
   jsonAppendChar(&jx, '[');
   for(i=0; i<argc; i++){
     jsonAppendSeparator(&jx);
-    jsonAppendValue(&jx, argv[i], 0);
+    jsonAppendValue(&jx, argv[i]);
   }
   jsonAppendChar(&jx, ']');
   jsonResult(&jx);
+  sqlite3_result_subtype(ctx, JSON_SUBTYPE);
 }
 
 
@@ -1138,7 +1107,7 @@ static void jsonArrayLengthFunc(
     JsonNode *pNode;
     if( argc==2 ){
       const char *zPath = (const char*)sqlite3_value_text(argv[1]);
-      pNode = jsonLookup(&x, zPath, 0, ctx, 0);
+      pNode = jsonLookup(&x, zPath, 0, ctx);
     }else{
       pNode = x.aNode;
     }
@@ -1180,7 +1149,7 @@ static void jsonExtractFunc(
   jsonAppendChar(&jx, '[');
   for(i=1; i<argc; i++){
     zPath = (const char*)sqlite3_value_text(argv[i]);
-    pNode = jsonLookup(&x, zPath, 0, ctx, 0);
+    pNode = jsonLookup(&x, zPath, 0, ctx);
     if( x.nErr ) break;
     if( argc>2 ){
       jsonAppendSeparator(&jx);
@@ -1196,6 +1165,7 @@ static void jsonExtractFunc(
   if( argc>2 && i==argc ){
     jsonAppendChar(&jx, ']');
     jsonResult(&jx);
+    sqlite3_result_subtype(ctx, JSON_SUBTYPE);
   }
   jsonReset(&jx);
   jsonParseReset(&x);
@@ -1234,10 +1204,11 @@ static void jsonObjectFunc(
     n = (u32)sqlite3_value_bytes(argv[i]);
     jsonAppendString(&jx, z, n);
     jsonAppendChar(&jx, ':');
-    jsonAppendValue(&jx, argv[i+1], 0);
+    jsonAppendValue(&jx, argv[i+1]);
   }
   jsonAppendChar(&jx, '}');
   jsonResult(&jx);
+  sqlite3_result_subtype(ctx, JSON_SUBTYPE);
 }
 
 
@@ -1263,7 +1234,7 @@ static void jsonRemoveFunc(
     for(i=1; i<(u32)argc; i++){
       zPath = (const char*)sqlite3_value_text(argv[i]);
       if( zPath==0 ) goto remove_done;
-      pNode = jsonLookup(&x, zPath, 0, ctx, 0);
+      pNode = jsonLookup(&x, zPath, 0, ctx);
       if( x.nErr ) goto remove_done;
       if( pNode ) pNode->jnFlags |= JNODE_REMOVE;
     }
@@ -1299,13 +1270,11 @@ static void jsonReplaceFunc(
   if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
   if( x.nNode ){
     for(i=1; i<(u32)argc; i+=2){
-      u8 jnFlags = JNODE_REPLACE;
       zPath = (const char*)sqlite3_value_text(argv[i]);
-      pNode = jsonLookup(&x, zPath, 0, ctx, &jnFlags);
+      pNode = jsonLookup(&x, zPath, 0, ctx);
       if( x.nErr ) goto replace_err;
       if( pNode ){
-        pNode->jnFlags &= ~JNODE_JSON;
-        pNode->jnFlags |= jnFlags;
+        pNode->jnFlags |= JNODE_REPLACE;
         pNode->iVal = i+1;
       }
     }
@@ -1351,18 +1320,16 @@ static void jsonSetFunc(
   if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
   if( x.nNode ){
     for(i=1; i<(u32)argc; i+=2){
-      u8 jnFlags = JNODE_REPLACE;
       zPath = (const char*)sqlite3_value_text(argv[i]);
       bApnd = 0;
-      pNode = jsonLookup(&x, zPath, &bApnd, ctx, &jnFlags);
+      pNode = jsonLookup(&x, zPath, &bApnd, ctx);
       if( x.oom ){
         sqlite3_result_error_nomem(ctx);
         goto jsonSetDone;
       }else if( x.nErr ){
         goto jsonSetDone;
       }else if( pNode && (bApnd || bIsSet) ){
-        pNode->jnFlags &= ~JNODE_JSON;
-        pNode->jnFlags |= jnFlags;
+        pNode->jnFlags |= JNODE_REPLACE;
         pNode->iVal = i+1;
       }
     }
@@ -1396,7 +1363,7 @@ static void jsonTypeFunc(
     JsonNode *pNode;
     if( argc==2 ){
       zPath = (const char*)sqlite3_value_text(argv[1]);
-      pNode = jsonLookup(&x, zPath, 0, ctx, 0);
+      pNode = jsonLookup(&x, zPath, 0, ctx);
     }else{
       pNode = x.aNode;
     }
@@ -1917,6 +1884,7 @@ int sqlite3_json_init(
      int flag;
      void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
   } aFunc[] = {
+    { "json",                 1, 0,   jsonRemoveFunc        },
     { "json_array",          -1, 0,   jsonArrayFunc         },
     { "json_array_length",    1, 0,   jsonArrayLengthFunc   },
     { "json_array_length",    2, 0,   jsonArrayLengthFunc   },
@@ -1934,7 +1902,6 @@ int sqlite3_json_init(
     /* DEBUG and TESTING functions */
     { "json_parse",           1, 0,   jsonParseFunc         },
     { "json_test1",           1, 0,   jsonTest1Func         },
-    { "json_nodecount",       1, 0,   jsonNodeCountFunc     },
 #endif
   };
 #ifndef SQLITE_OMIT_VIRTUALTABLE