From: drh <>
Date: Tue, 28 Nov 2023 00:27:58 +0000 (+0000)
Subject: More aggressive use of jsonBlobEdit().  Improvements to the MergePatch
X-Git-Tag: version-3.45.0~116^2~50
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f46f89df975100808dc096be69c577206a587123;p=thirdparty%2Fsqlite.git

More aggressive use of jsonBlobEdit().  Improvements to the MergePatch
implementation sketch.

FossilOrigin-Name: fbca9570fd2e1465739e4d3a8d9bb40fad594fd78ab49b2cb34efa27ebdd8361
---

diff --git a/manifest b/manifest
index 6ae9cbf521..eb129dd02f 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Add\suntested\s(#ifdefed-out)\scode\sfor\sthe\sMergePatch\salgorithm\sagainst\sJSONB.\nAdd\s(and\stest)\sthe\sjsonBlobEdit()\sroutine\sthat\sis\sneeded\sby\sthe\snew\sMergePatch.
-D 2023-11-27T23:46:12.954
+C More\saggressive\suse\sof\sjsonBlobEdit().\s\sImprovements\sto\sthe\sMergePatch\nimplementation\ssketch.
+D 2023-11-28T00:27:58.169
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -688,7 +688,7 @@ 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 7d6387920736cd9b78a4211771265c4c574284613d8e63f43b3ce7bc160da498
+F src/json.c a91647a3c56298ff94bb2d5a989e8e329c4435e3a0ae9760b04b46c7b2083541
 F src/legacy.c d7874bc885906868cd51e6c2156698f2754f02d9eee1bae2d687323c3ca8e5aa
 F src/loadext.c 7432c944ff197046d67a1207790a1b13eec4548c85a9457eb0896bb3641dfb36
 F src/main.c 1b89f3de98d1b59fec5bac1d66d6ece21f703821b8eaa0d53d9604c35309f6f9
@@ -2145,8 +2145,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P af267868562e0799ad691dccad05f17afbc34d609eede8c55f57d209290246ef
-R 47ffcc493583e45ee7703e45cf1805e3
+P 4d353387fc10e1038cfdd86e66007bf728c231a928e588897bbee0fbfe76f225
+R 42f4ec3bb9c19f358b256294966169e5
 U drh
-Z 2cedbcb9affb9f675b8d832bfea283a4
+Z 551901455bde8067c499befcab52664b
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index a4814c0752..6460236f38 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-4d353387fc10e1038cfdd86e66007bf728c231a928e588897bbee0fbfe76f225
\ No newline at end of file
+fbca9570fd2e1465739e4d3a8d9bb40fad594fd78ab49b2cb34efa27ebdd8361
\ No newline at end of file
diff --git a/src/json.c b/src/json.c
index 99205decf1..0138db5183 100644
--- a/src/json.c
+++ b/src/json.c
@@ -3809,8 +3809,8 @@ static void jsonAfterEditSizeAdjust(JsonParse *pParse, u32 iRoot){
 ** nDel may be zero, in which case no bytes are removed.  But iDel is
 ** still important as new bytes will be insert beginning at iDel.
 **
-** nIns may be zero, in which case no new bytes are inserted.  aIns might
-** be a NULL pointer in this case.
+** aIns may be zero, in which case space is created to hold nIns bytes
+** beginning at iDel, but that space is uninitialized.
 **
 ** Set pParse->oom if an OOM occurs.
 */
@@ -3833,7 +3833,7 @@ static void jsonBlobEdit(
     pParse->nBlob += d;
     pParse->delta += d;
   }
-  if( nIns ) memcpy(&pParse->aBlob[iDel], aIns, nIns);
+  if( nIns && aIns ) memcpy(&pParse->aBlob[iDel], aIns, nIns);
 }
 
 /*
@@ -3940,19 +3940,14 @@ static u32 jsonLookupBlobStep(
       ix.nBlobAlloc = sizeof(aLabel);
       jsonBlobAppendNodeType(&ix,JSONB_TEXTRAW, nKey);
       if( jsonBlobMakeEditable(pParse, ix.nBlob+nKey) ){
-        /* This is similar to jsonBlobEdit() except that the inserted
-        ** bytes come from two different places, ix.aBlob and pParse->aBlob. */
         nIns = ix.nBlob + nKey + pParse->nIns;
+        jsonBlobEdit(pParse, j, 0, 0, nIns);
         assert( pParse->nBlob + pParse->nIns <= pParse->nBlobAlloc );
-        memmove(&pParse->aBlob[j+nIns], &pParse->aBlob[j],
-                pParse->nBlob - j);
         memcpy(&pParse->aBlob[j], ix.aBlob, ix.nBlob);
         k = j + ix.nBlob;
         memcpy(&pParse->aBlob[k], zKey, nKey);
         k += nKey;
         memcpy(&pParse->aBlob[k], pParse->aIns, pParse->nIns);
-        pParse->delta = nIns;
-        pParse->nBlob += nIns;
         jsonAfterEditSizeAdjust(pParse, iRoot);
       }
       return j;
@@ -5030,13 +5025,13 @@ static JsonNode *jsonMergePatch(
 **     else:
 **       return Patch
 **
-** Here is the same algorithm restrictured to show the actual
+** Here is an equivalent algorithm restructured to show the actual
 ** implementation:
 **
 ** 01   define MergePatch(Target, Patch):
 ** 02      if Patch is not an Object:
 ** 03         return Patch
-** 04      else:  // if Patch is an Object:
+** 04      else: // if Patch is an Object
 ** 05         if Target is not an Object:
 ** 06            Target = {}
 ** 07      for each Name/Value pair in Patch:
@@ -5046,8 +5041,11 @@ static JsonNode *jsonMergePatch(
 ** 11            else
 ** 12               Target[name] = MergePatch(Target[Name], Value)
 ** 13         else if Value is not NULL:
-** 14            Target[name] = RemoveNullVAlues(Value)
-** 15      return Target
+** 14            if Value is not an Object:
+** 15               Target[name] = Value
+** 16            else:
+** 17               Target[name] = MergePatch('{}',value)
+** 18      return Target
 **  |
 **  ^---- Line numbers referenced in comments in the implementation
 */
@@ -5161,10 +5159,19 @@ static int jsonMergePatchBlob(
       }        
     }else if( x>0 ){  /* Algorithm line 13 */
       /* No match and patch value is not NULL */
-      jsonBlobEdit(pTarget, iTEnd, 0,
-                   pPatch->aBlob+iPValue, szPValue+nPValue);
-      if( pTarget->oom ) return JSON_MERGE_OOM;
-      jsonBlobRemoveNullsFromObject(pTarget, iTEnd);
+      if( pPatch->aBlob[iPValue] & 0x0f)!=JSONB_OBJECT ){
+        jsonBlobEdit(pTarget, iTEnd, 0,
+                     pPatch->aBlob+iPValue, szPValue+nPValue, 0, 0);
+        if( pTarget->oom ) return JSON_MERGE_OOM;
+      }else{
+        u32 szNew = szPLabel+nPLabel;
+        jsonBlobEdit(pTarget, iTEnd, 0, 0, szNew+1);
+        if( pTarget->oom ) return JSON_MERGE_OOM;
+        memcpy(&pTarget->aBlob[iTEnd], &pPatch->aBlob[iPLabel], szNew);
+        pTarget->aBlob[iTEnd+szNew] = 0x00;
+        rc = jsonMergePatch(pTarget, iTEnd+szNew, pPatch, iPValue);
+        if( rc ) return rc;
+      }
     }
   }
   jsonAfterEditSizeAdjust(pTarget, iTarget);