Enhance the JSONB lookup routine with logic to apply edits. The new logic is

currently unused and hence untested but does not create any regressions.

FossilOrigin-Name: b12110276fc15d1b6b0cc455f89747ace7a09650d5ba433d8bb431bb4e5bc951

diff --git a/manifest b/manifest
index 869a09d63f91398b5ff35c09e2b97f830ad69f89..9aadbdf94146bda24aefa225d1dafe85d74c7aa3 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Merge\sall\sthe\slatest\strunk\sfixes\sand\senhancements\sinto\sthe\sjsonb\sbranch.
-D 2023-11-03T11:35:33.434
+C Enhance\sthe\sJSONB\slookup\sroutine\swith\slogic\sto\sapply\sedits.\s\sThe\snew\slogic\sis\ncurrently\sunused\sand\shence\suntested\sbut\sdoes\snot\screate\sany\sregressions.
+D 2023-11-03T12:09:22.342
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -683,7 +683,7 @@ 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 2c0599c54aef24739015a0b7f7b569adecd760e4d06afd3d9c01c8c53713d3f0
+F src/json.c e109da4d5f29e239db837dad09a886a78b6a217592ea8c71e3b584483ce9b179
 F src/legacy.c d7874bc885906868cd51e6c2156698f2754f02d9eee1bae2d687323c3ca8e5aa
 F src/loadext.c 7432c944ff197046d67a1207790a1b13eec4548c85a9457eb0896bb3641dfb36
 F src/main.c e1bc8864834697503d370d94613be945d05ca1c5ebdda43e7d5c8ee8c48d433c
@@ -2142,8 +2142,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P a420a4f7ff76b0e9cf5f6d515ccfa31e526d58f4001a4015a367e2aa3c82091f 15b618e92a2708cc83256947736de8c494a9985a77e38bd5efc7e51e72cba344
-R 7bce1ab3b73fc9ca8b3b94f2470fc2d6
+P b089bf46374b374d02d7654c65eb3e75d1777638b398061e47644af0dab48c9b
+R 02d78f9919449761c67674ad6f60265a
 U drh
-Z 13124fe09b7592eb801d594e79ae949a
+Z f8a451c94f8b9175a3b99dd9c9c86acd
 # Remove this line to create a well-formed Fossil manifest.

diff --git a/manifest.uuid b/manifest.uuid
index 71f504a4200dde10901680da0b70a6adf0789545..c8ced97e73d014abbf91e74fda516d6446e494a9 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-b089bf46374b374d02d7654c65eb3e75d1777638b398061e47644af0dab48c9b
\ No newline at end of file
+b12110276fc15d1b6b0cc455f89747ace7a09650d5ba433d8bb431bb4e5bc951
\ No newline at end of file

diff --git a/src/json.c b/src/json.c
index 48d456e53640a9b99ae5c27060ef9da7ac710a4e..e998af5230d620c7843774fea7c6b3efb95e5af9 100644 (file)
--- a/src/json.c
+++ b/src/json.c
@@ -341,8 +341,19 @@ struct JsonParse {
   u32 nBlob;         /* Bytes of aBlob[] actually used */
   u32 nBlobAlloc;    /* Bytes allocated to aBlob[] */
   u8 *aBlob;         /* BLOB representation of zJson */
+  /* Search and edit information.  See jsonLookupBlobStep() */
+  u8 eEdit;          /* Edit operation to apply */
+  int delta;         /* Size change due to the edit */
+  u32 nIns;          /* Number of bytes to insert */
+  u8 *aIns;          /* Content to be inserted */
 };
 
+/* Allowed values for JsonParse.eEdit */
+#define JEDIT_DEL   0x01   /* Delete if exists */
+#define JEDIT_INS   0x02   /* Insert if not exists */
+#define JEDIT_REPL  0x04   /* Overwrite if exists */
+#define JEDIT_SET   0x08   /* Insert or overwrite */
+
 /*
 ** Maximum nesting depth of JSON for this implementation.
 **
@@ -720,8 +731,6 @@ static void jsonAppendNormalizedReal(JsonString *p, const char *zIn, u32 N){
   }
 }
 
-
-
 /*
 ** Append an sqlite3_value (such as a function parameter) to the JSON
 ** string under construction in p.
@@ -2558,6 +2567,31 @@ static int jsonBlobExpand(JsonParse *pParse, u32 N){
   return 0;
 }
 
+/*
+** If pParse->aBlob is not previously editable (because it is taken
+** from sqlite3_value_blob(), as indicated by the fact that
+** pParse->nBlobAlloc==0 and pParse->nBlob>0) then make it editable
+** by making a copy into space obtained from malloc.
+**
+** Return true on success.  Return false on OOM.
+*/
+static int jsonBlobMakeEditable(JsonParse *pParse){
+  u8 *aOld;
+  u32 nSize;
+  if( pParse->nBlobAlloc>0 ) return 1;
+  aOld = pParse->aBlob;
+  nSize = pParse->nBlob + pParse->nIns;
+  if( nSize>100 ) nSize -= 100;
+  pParse->aBlob = 0;
+  if( jsonBlobExpand(pParse, nSize) ){
+    return 0;
+  }
+  assert( pParse->nBlobAlloc >= pParse->nBlob + pParse->nIns );
+  memcpy(pParse->aBlob, aOld, pParse->nBlob);
+  return 1;
+}
+
+
 /* Expand pParse->aBlob and append N bytes.
 **
 ** Return the number of errors.
@@ -3767,12 +3801,24 @@ static u32 jsonbArrayCount(JsonParse *pParse, u32 iRoot){
   return k;
 }
 
+/*
+** Edit the size of the element at iRoot by the amount in pParse->delta.
+*/
+static void jsonAfterEditSizeAdjust(JsonParse *pParse, u32 iRoot){
+  u32 sz;
+  assert( pParse->delta==0 );
+  (void)jsonbPayloadSize(pParse, iRoot, &sz);
+  sz += pParse->delta;
+  jsonBlobChangePayloadSize(pParse, iRoot, sz);
+}
+
 /*
 ** Error returns from jsonLookupBlobStep()
 */
 #define JSON_BLOB_ERROR      0xffffffff
 #define JSON_BLOB_NOTFOUND   0xfffffffe
 #define JSON_BLOB_PATHERROR  0xfffffffd
+#define JSON_BLOB_ISERROR(x) ((x)>=JSON_BLOB_PATHERROR)
 
 /*
 ** Search along zPath to find the Json element specified.  Return an
@@ -3785,12 +3831,39 @@ static u32 jsonLookupBlobStep(
   u32 iRoot,              /* Begin the search at this element of aBlob[] */
   const char *zPath       /* The path to search */
 ){
-  u32 i, j, k, nKey, sz, n, iEnd;
+  u32 i, j, k, nKey, sz, n, iEnd, rc;
   const char *zKey;
   u8 x;
 
-  if( pParse->oom ) return 0;
-  if( zPath[0]==0 ) return iRoot;
+  if( zPath[0]==0 ){
+    if( pParse->eEdit && jsonBlobMakeEditable(pParse) ){
+      n = jsonbPayloadSize(pParse, iRoot, &sz);
+      sz += n;
+      if( pParse->eEdit==JEDIT_DEL ){
+        memmove(&pParse->aBlob[iRoot], &pParse->aBlob[iRoot+sz],
+                pParse->nBlob - iRoot);
+        pParse->nBlob -= n;
+        pParse->delta = -(int)n;
+      }else if( pParse->eEdit==JEDIT_INS ){
+        /* Already exists, so json_insert() is a no-op */
+      }else{
+        /* json_set() or json_replace() */
+        int d = (int)pParse->nIns - (int)sz;
+        pParse->delta = d;
+        if( d!=0 ){
+          if( pParse->nBlob + d > pParse->nBlobAlloc ){
+            jsonBlobExpand(pParse, pParse->nBlob+d);
+            if( pParse->oom ) return iRoot;
+          }
+          memmove(&pParse->aBlob[iRoot+pParse->nIns],
+                  &pParse->aBlob[iRoot+sz],
+                  pParse->nBlob - iRoot - sz);
+        }
+        memcpy(&pParse->aBlob[iRoot], pParse->aIns, pParse->nIns);
+      }
+    }
+    return iRoot;
+  }
   if( zPath[0]=='.' ){
     x = pParse->aBlob[iRoot];
     zPath++;
@@ -3828,7 +3901,9 @@ static u32 jsonLookupBlobStep(
         if( ((pParse->aBlob[j])&0x0f)>JSONB_OBJECT ) return JSON_BLOB_ERROR;
         n = jsonbPayloadSize(pParse, j, &sz);
         if( n==0 || j+n+sz>iEnd ) return JSON_BLOB_ERROR;
-        return jsonLookupBlobStep(pParse, j, &zPath[i]);
+        rc = jsonLookupBlobStep(pParse, j, &zPath[i]);
+        if( pParse->delta ) jsonAfterEditSizeAdjust(pParse, iRoot);
+        return rc;
       }
       j = k+sz;
       if( ((pParse->aBlob[j])&0x0f)>JSONB_OBJECT ) return JSON_BLOB_ERROR;
@@ -3872,7 +3947,9 @@ static u32 jsonLookupBlobStep(
     iEnd = j+sz;
     while( j<iEnd ){
       if( k==0 ){
-        return jsonLookupBlobStep(pParse, j, &zPath[i+1]);
+        rc = jsonLookupBlobStep(pParse, j, &zPath[i+1]);
+        if( pParse->delta ) jsonAfterEditSizeAdjust(pParse, iRoot);
+        return rc;
       }
       k--;
       n = jsonbPayloadSize(pParse, j, &sz);
@@ -3880,9 +3957,20 @@ static u32 jsonLookupBlobStep(
       j += n+sz;
     }
     if( j>iEnd ) return JSON_BLOB_ERROR;
+    if( k>1 ) return JSON_BLOB_NOTFOUND;
   }else{
     return JSON_BLOB_PATHERROR; 
   }
+  if( pParse->eEdit==JEDIT_INS && jsonBlobMakeEditable(pParse) ){
+    assert( pParse->nBlob + pParse->nIns <= pParse->nBlobAlloc );
+    memmove(&pParse->aBlob[j], &pParse->aBlob[j+pParse->nIns],
+            pParse->nBlob - j);
+    memcpy(&pParse->aBlob[j], pParse->aIns, pParse->nIns);
+    pParse->delta = pParse->nIns;
+    pParse->nBlob += pParse->nIns;
+    jsonAfterEditSizeAdjust(pParse, iRoot);
+    return j;
+  }
   return JSON_BLOB_NOTFOUND;
 }