[sql] Import SQLite 3.17.0.

third_party/sqlite/src/ext/misc/json1.c

 /*
 ** 2015-08-12
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
 **
 **    May you do good and not evil.
 **    May you find forgiveness for yourself and forgive others.
 **    May you share freely, never taking more than you give.
 **
 ******************************************************************************
 **
 ** This SQLite extension implements JSON functions.  The interface is
 ** modeled after MySQL JSON functions:
 **
 **     https://dev.mysql.com/doc/refman/5.7/en/json.html
 **
 ** For the time being, all JSON is stored as pure text.  (We might add
 ** a JSONB type in the future which stores a binary encoding of JSON in
 ** a BLOB, but there is no support for JSONB in the current implementation.
 ** This implementation parses JSON text at 250 MB/s, so it is hard to see
 ** how JSONB might improve on that.)
 */
 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_JSON1)
-#if !defined(_SQLITEINT_H_)
+#if !defined(SQLITEINT_H)
 #include "sqlite3ext.h"
 #endif
 SQLITE_EXTENSION_INIT1
 #include <assert.h>
 #include <string.h>
 #include <stdlib.h>
 #include <stdarg.h>
 
-#define UNUSED_PARAM(X)  (void)(X)
+/* Mark a function parameter as unused, to suppress nuisance compiler
+** warnings. */
+#ifndef UNUSED_PARAM
+# define UNUSED_PARAM(X)  (void)(X)
+#endif
 
 #ifndef LARGEST_INT64
 # define LARGEST_INT64  (0xffffffff|(((sqlite3_int64)0x7fffffff)<<32))
 # define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64)
 #endif
 
 /*
 ** Versions of isspace(), isalnum() and isdigit() to which it is safe
 ** to pass signed char values.
 */
 #ifdef sqlite3Isdigit
    /* Use the SQLite core versions if this routine is part of the
    ** SQLite amalgamation */
-#  define safe_isdigit(x) sqlite3Isdigit(x)
-#  define safe_isalnum(x) sqlite3Isalnum(x)
+#  define safe_isdigit(x)  sqlite3Isdigit(x)
+#  define safe_isalnum(x)  sqlite3Isalnum(x)
+#  define safe_isxdigit(x) sqlite3Isxdigit(x)
 #else
    /* Use the standard library for separate compilation */
 #include <ctype.h>  /* amalgamator: keep */
-#  define safe_isdigit(x) isdigit((unsigned char)(x))
-#  define safe_isalnum(x) isalnum((unsigned char)(x))
+#  define safe_isdigit(x)  isdigit((unsigned char)(x))
+#  define safe_isalnum(x)  isalnum((unsigned char)(x))
+#  define safe_isxdigit(x) isxdigit((unsigned char)(x))
 #endif
 
 /*
 ** Growing our own isspace() routine this way is twice as fast as
 ** the library isspace() function, resulting in a 7% overall performance
 ** 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,
@@ skipping 204 matching lines @@
 /* Append the N-byte string in zIn to the end of the JsonString string
 ** under construction.  Enclose the string in "..." and escape
 ** any double-quotes or backslash characters contained within the
 ** string.
 */
 static void jsonAppendString(JsonString *p, const char *zIn, u32 N){
   u32 i;
   if( (N+p->nUsed+2 >= p->nAlloc) && jsonGrow(p,N+2)!=0 ) return;
   p->zBuf[p->nUsed++] = '"';
   for(i=0; i<N; i++){
-    char c = zIn[i];
+    unsigned char c = ((unsigned const char*)zIn)[i];
     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 ){
+      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
+      };
+      assert( sizeof(aSpecial)==32 );
+      assert( aSpecial['\b']=='b' );
+      assert( aSpecial['\f']=='f' );
+      assert( aSpecial['\n']=='n' );
+      assert( aSpecial['\r']=='r' );
+      assert( aSpecial['\t']=='t' );
+      if( aSpecial[c] ){
+        c = aSpecial[c];
+        goto json_simple_escape;
+      }
+      if( (p->nUsed+N+7+i > p->nAlloc) && jsonGrow(p,N+7-i)!=0 ) return;
+      p->zBuf[p->nUsed++] = '\\';
+      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++] = c;
   }
   p->zBuf[p->nUsed++] = '"';
   assert( p->nUsed<p->nAlloc );
 }
 
 /*
 ** Append a function parameter value to the JSON string under 
 ** construction.
@@ skipping 20 matching lines @@
       if( sqlite3_value_subtype(pValue)==JSON_SUBTYPE ){
         jsonAppendRaw(p, z, n);
       }else{
         jsonAppendString(p, z, n);
       }
       break;
     }
     default: {
       if( p->bErr==0 ){
         sqlite3_result_error(p->pCtx, "JSON cannot hold BLOB values", -1);
-        p->bErr = 1;
+        p->bErr = 2;
         jsonReset(p);
       }
       break;
     }
   }
 }
 
 
 /* Make the JSON in p the result of the SQL function.
 */
@@ skipping 225 matching lines @@
           break;
         }
         for(i=1, j=0; i<n-1; i++){
           char c = z[i];
           if( c!='\\' ){
             zOut[j++] = c;
           }else{
             c = z[++i];
             if( c=='u' ){
               u32 v = 0, k;
-              for(k=0; k<4 && i<n-2; i++, k++){
+              for(k=0; k<4; i++, k++){
+                assert( i<n-2 );
                 c = z[i+1];
-                if( c>='0' && c<='9' ) v = v*16 + c - '0';
-                else if( c>='A' && c<='F' ) v = v*16 + c - 'A' + 10;
-                else if( c>='a' && c<='f' ) v = v*16 + c - 'a' + 10;
-                else break;
+                assert( safe_isxdigit(c) );
+                if( c<='9' ) v = v*16 + c - '0';
+                else if( c<='F' ) v = v*16 + c - 'A' + 10;
+                else v = v*16 + c - 'a' + 10;
               }
               if( v==0 ) break;
               if( v<=0x7f ){
                 zOut[j++] = (char)v;
               }else if( v<=0x7ff ){
                 zOut[j++] = (char)(0xc0 | (v>>6));
                 zOut[j++] = 0x80 | (v&0x3f);
               }else{
                 zOut[j++] = (char)(0xe0 | (v>>12));
                 zOut[j++] = 0x80 | ((v>>6)&0x3f);
@@ skipping 84 matching lines @@
   p = &pParse->aNode[pParse->nNode];
   p->eType = (u8)eType;
   p->jnFlags = 0;
   p->iVal = 0;
   p->n = n;
   p->u.zJContent = zContent;
   return pParse->nNode++;
 }
 
 /*
+** Return true if z[] begins with 4 (or more) hexadecimal digits
+*/
+static int jsonIs4Hex(const char *z){
+  int i;
+  for(i=0; i<4; i++) if( !safe_isxdigit(z[i]) ) return 0;
+  return 1;
+}
+
+/*
 ** Parse a single JSON value which begins at pParse->zJson[i].  Return the
 ** index of the first character past the end of the value parsed.
 **
 ** Return negative for a syntax error.  Special cases:  return -2 if the
 ** first non-whitespace character is '}' and return -3 if the first
 ** non-whitespace character is ']'.
 */
 static int jsonParseValue(JsonParse *pParse, u32 i){
   char c;
   u32 j;
@@ skipping 53 matching lines @@
     return j+1;
   }else if( c=='"' ){
     /* Parse string */
     u8 jnFlags = 0;
     j = i+1;
     for(;;){
       c = pParse->zJson[j];
       if( c==0 ) return -1;
       if( c=='\\' ){
         c = pParse->zJson[++j];
-        if( c==0 ) return -1;
-        jnFlags = JNODE_ESCAPE;
+        if( c=='"' || c=='\\' || c=='/' || c=='b' || c=='f'
+           || c=='n' || c=='r' || c=='t'
+           || (c=='u' && jsonIs4Hex(pParse->zJson+j+1)) ){
+          jnFlags = JNODE_ESCAPE;
+        }else{
+          return -1;
+        }
       }else if( c=='"' ){
         break;
       }
       j++;
     }
     jsonParseAddNode(pParse, JSON_STRING, j+1-i, &pParse->zJson[i]);
     if( !pParse->oom ) pParse->aNode[pParse->nNode-1].jnFlags = jnFlags;
     return j+1;
   }else if( c=='n'
          && strncmp(pParse->zJson+i,"null",4)==0
@@ skipping 414 matching lines @@
   UNUSED_PARAM(argc);
   sqlite3_result_int(ctx, sqlite3_value_subtype(argv[0])==JSON_SUBTYPE);
 }
 #endif /* SQLITE_DEBUG */
 
 /****************************************************************************
 ** Scalar SQL function implementations
 ****************************************************************************/
 
 /*
+** Implementation of the json_QUOTE(VALUE) function.  Return a JSON value
+** corresponding to the SQL value input.  Mostly this means putting 
+** double-quotes around strings and returning the unquoted string "null"
+** when given a NULL input.
+*/
+static void jsonQuoteFunc(
+  sqlite3_context *ctx,
+  int argc,
+  sqlite3_value **argv
+){
+  JsonString jx;
+  UNUSED_PARAM(argc);
+
+  jsonInit(&jx, ctx);
+  jsonAppendValue(&jx, argv[0]);
+  jsonResult(&jx);
+  sqlite3_result_subtype(ctx, JSON_SUBTYPE);
+}
+
+/*
 ** Implementation of the json_array(VALUE,...) function.  Return a JSON
 ** array that contains all values given in arguments.  Or if any argument
 ** is a BLOB, throw an error.
 */
 static void jsonArrayFunc(
   sqlite3_context *ctx,
   int argc,
   sqlite3_value **argv
 ){
   int i;
@@ skipping 324 matching lines @@
 ** json_group_array(VALUE)
 **
 ** Return a JSON array composed of all values in the aggregate.
 */
 static void jsonArrayStep(
   sqlite3_context *ctx,
   int argc,
   sqlite3_value **argv
 ){
   JsonString *pStr;
+  UNUSED_PARAM(argc);
   pStr = (JsonString*)sqlite3_aggregate_context(ctx, sizeof(*pStr));
   if( pStr ){
     if( pStr->zBuf==0 ){
       jsonInit(pStr, ctx);
       jsonAppendChar(pStr, '[');
     }else{
       jsonAppendChar(pStr, ',');
       pStr->pCtx = ctx;
     }
     jsonAppendValue(pStr, argv[0]);
   }
 }
 static void jsonArrayFinal(sqlite3_context *ctx){
   JsonString *pStr;
   pStr = (JsonString*)sqlite3_aggregate_context(ctx, 0);
   if( pStr ){
     pStr->pCtx = ctx;
     jsonAppendChar(pStr, ']');
     if( pStr->bErr ){
-      sqlite3_result_error_nomem(ctx);
+      if( pStr->bErr==1 ) sqlite3_result_error_nomem(ctx);
       assert( pStr->bStatic );
     }else{
       sqlite3_result_text(ctx, pStr->zBuf, pStr->nUsed,
                           pStr->bStatic ? SQLITE_TRANSIENT : sqlite3_free);
       pStr->bStatic = 1;
     }
   }else{
     sqlite3_result_text(ctx, "[]", 2, SQLITE_STATIC);
   }
   sqlite3_result_subtype(ctx, JSON_SUBTYPE);
 }
 
 /*
 ** json_group_obj(NAME,VALUE)
 **
 ** Return a JSON object composed of all names and values in the aggregate.
 */
 static void jsonObjectStep(
   sqlite3_context *ctx,
   int argc,
   sqlite3_value **argv
 ){
   JsonString *pStr;
   const char *z;
   u32 n;
+  UNUSED_PARAM(argc);
   pStr = (JsonString*)sqlite3_aggregate_context(ctx, sizeof(*pStr));
   if( pStr ){
     if( pStr->zBuf==0 ){
       jsonInit(pStr, ctx);
       jsonAppendChar(pStr, '{');
     }else{
       jsonAppendChar(pStr, ',');
       pStr->pCtx = ctx;
     }
     z = (const char*)sqlite3_value_text(argv[0]);
     n = (u32)sqlite3_value_bytes(argv[0]);
     jsonAppendString(pStr, z, n);
     jsonAppendChar(pStr, ':');
     jsonAppendValue(pStr, argv[1]);
   }
 }
 static void jsonObjectFinal(sqlite3_context *ctx){
   JsonString *pStr;
   pStr = (JsonString*)sqlite3_aggregate_context(ctx, 0);
   if( pStr ){
     jsonAppendChar(pStr, '}');
     if( pStr->bErr ){
-      sqlite3_result_error_nomem(ctx);
+      if( pStr->bErr==1 ) sqlite3_result_error_nomem(ctx);
       assert( pStr->bStatic );
     }else{
       sqlite3_result_text(ctx, pStr->zBuf, pStr->nUsed,
                           pStr->bStatic ? SQLITE_TRANSIENT : sqlite3_free);
       pStr->bStatic = 1;
     }
   }else{
     sqlite3_result_text(ctx, "{}", 2, SQLITE_STATIC);
   }
   sqlite3_result_subtype(ctx, JSON_SUBTYPE);
@@ skipping 257 matching lines @@
       if( p->bRecursive ){
         JsonString x;
         jsonInit(&x, ctx);
         jsonEachComputePath(p, &x, p->sParse.aUp[p->i]);
         jsonResult(&x);
         break;
       }
       /* For json_each() path and root are the same so fall through
       ** into the root case */
     }
-    case JEACH_ROOT: {
+    default: {
       const char *zRoot = p->zRoot;
-       if( zRoot==0 ) zRoot = "$";
+      if( zRoot==0 ) zRoot = "$";
       sqlite3_result_text(ctx, zRoot, -1, SQLITE_STATIC);
       break;
     }
     case JEACH_JSON: {
       assert( i==JEACH_JSON );
       sqlite3_result_text(ctx, p->sParse.zJson, -1, SQLITE_STATIC);
       break;
     }
   }
   return SQLITE_OK;
@@ skipping 198 matching lines @@
      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   },
     { "json_extract",        -1, 0,   jsonExtractFunc       },
     { "json_insert",         -1, 0,   jsonSetFunc           },
     { "json_object",         -1, 0,   jsonObjectFunc        },
+    { "json_quote",           1, 0,   jsonQuoteFunc         },
     { "json_remove",         -1, 0,   jsonRemoveFunc        },
     { "json_replace",        -1, 0,   jsonReplaceFunc       },
     { "json_set",            -1, 1,   jsonSetFunc           },
     { "json_type",            1, 0,   jsonTypeFunc          },
     { "json_type",            2, 0,   jsonTypeFunc          },
     { "json_valid",           1, 0,   jsonValidFunc         },
 
 #if SQLITE_DEBUG
     /* DEBUG and TESTING functions */
     { "json_parse",           1, 0,   jsonParseFunc         },
@@ skipping 46 matching lines @@
   sqlite3 *db, 
   char **pzErrMsg, 
   const sqlite3_api_routines *pApi
 ){
   SQLITE_EXTENSION_INIT2(pApi);
   (void)pzErrMsg;  /* Unused parameter */
   return sqlite3Json1Init(db);
 }
 #endif
 #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_JSON1) */