Add the json_pretty(J) function for pretty-printing of JSON. An optional

2nd argument is text used for indentation, with a default value being four
spaces.

FossilOrigin-Name: 39552bd36c06fe9ee346cb71e0659baceccde031b67c0974f2dd14eb11ebc055

diff --git a/manifest b/manifest
index da940666474e3f6b1bf4cf2412a8550286291bfe..682a374dee23f8cd9ff5e01077e5bc2c1e871864 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Correction\sto\sthe\sprevious\scheck-in.
-D 2024-03-06T12:28:55.128
+C Add\sthe\sjson_pretty(J)\sfunction\sfor\spretty-printing\sof\sJSON.\s\sAn\soptional\n2nd\sargument\sis\stext\sused\sfor\sindentation,\swith\sa\sdefault\svalue\sbeing\sfour\nspaces.
+D 2024-03-06T14:30:42.046
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -710,7 +710,7 @@ 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 9337dac9d9d4c77461db55fd3e06e4d006f4283cb1da2b3a9b1f8d750701583e
+F src/json.c e2e40760d6689134c3e2ece38c6a496b34ff5e2661a8f238444a119af666fdce
 F src/legacy.c d7874bc885906868cd51e6c2156698f2754f02d9eee1bae2d687323c3ca8e5aa
 F src/loadext.c 7432c944ff197046d67a1207790a1b13eec4548c85a9457eb0896bb3641dfb36
 F src/main.c 438b95162acfa17b7d218f586f5bde11d6ae82bcf030c9611fc537556870ad6b
@@ -2176,8 +2176,11 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 027e5336acc26f57f21df4980928731026c30cf88688fa0b66f13ffa0b5da3a0
-R ee785ecad1867a820bb9e665fd92d3e8
+P 483fa2969e1e10cd8e8d2f9e3027871c65b1360b6c23897efe3ce63a3a55ae13
+R cdcb4f4f681bccfe01ba6f525ed68e3e
+T *branch * json-pretty
+T *sym-json-pretty *
+T -sym-trunk *
 U drh
-Z 74daf43f110405d8b8bf503998b8174f
+Z 040cd116c25b3e34e2b8acda05bc14c7
 # Remove this line to create a well-formed Fossil manifest.

diff --git a/manifest.uuid b/manifest.uuid
index dba854ccd33841b949b504f3bb8dc5e8f6c0684a..0340f39ad24656f45bb0d2c7e7540517286f9c7a 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-483fa2969e1e10cd8e8d2f9e3027871c65b1360b6c23897efe3ce63a3a55ae13
\ No newline at end of file
+39552bd36c06fe9ee346cb71e0659baceccde031b67c0974f2dd14eb11ebc055
\ No newline at end of file

diff --git a/src/json.c b/src/json.c
index fe7f9388835ff11fd48302aeaeb9f9bc8dcb1bf6..44ae846461f9597d286cd9c6caf02d255abf21df 100644 (file)
--- a/src/json.c
+++ b/src/json.c
@@ -563,7 +563,6 @@ static void jsonAppendRawNZ(JsonString *p, const char *zIn, u32 N){
   }
 }
 
-
 /* Append formatted text (not to exceed N bytes) to the JsonString.
 */
 static void jsonPrintf(int N, JsonString *p, const char *zFormat, ...){
@@ -2336,6 +2335,112 @@ static u32 jsonTranslateBlobToText(
   return i+n+sz;
 }
 
+/* Context for recursion of json_pretty()
+*/
+typedef struct JsonPretty JsonPretty;
+struct JsonPretty {
+  JsonParse *pParse;        /* The BLOB being rendered */
+  JsonString *pOut;         /* Generate pretty output into this string */
+  const char *zIndent;      /* Use this text for indentation */
+  u32 szIndent;             /* Bytes in zIndent[] */
+  u32 nIndent;              /* Current level of indentation */
+};
+
+/* Append indentation to the pretty JSON under construction */
+static void jsonPrettyIndent(JsonPretty *pPretty){
+  u32 jj;
+  for(jj=0; jj<pPretty->nIndent; jj++){
+    jsonAppendRaw(pPretty->pOut, pPretty->zIndent, pPretty->szIndent);
+  }
+}
+
+/*
+** Translate the binary JSONB representation of JSON beginning at
+** pParse->aBlob[i] into a JSON text string.  Append the JSON
+** text onto the end of pOut.  Return the index in pParse->aBlob[]
+** of the first byte past the end of the element that is translated.
+**
+** This is a variant of jsonTranslateBlobToText() that "pretty-prints"
+** the output.  Extra whitespace is inserted to make the JSON easier
+** for humans to read.
+**
+** If an error is detected in the BLOB input, the pOut->eErr flag
+** might get set to JSTRING_MALFORMED.  But not all BLOB input errors
+** are detected.  So a malformed JSONB input might either result
+** in an error, or in incorrect JSON.
+**
+** The pOut->eErr JSTRING_OOM flag is set on a OOM.
+*/
+static u32 jsonTranslateBlobToPrettyText(
+  JsonPretty *pPretty,       /* Pretty-printing context */
+  u32 i                      /* Start rendering at this index */
+){
+  u32 sz, n, j, iEnd;
+  const JsonParse *pParse = pPretty->pParse;
+  JsonString *pOut = pPretty->pOut;
+  n = jsonbPayloadSize(pParse, i, &sz);
+  if( n==0 ){
+    pOut->eErr |= JSTRING_MALFORMED;
+    return pParse->nBlob+1;
+  }
+  switch( pParse->aBlob[i] & 0x0f ){
+    case JSONB_ARRAY: {
+      j = i+n;
+      iEnd = j+sz;
+      jsonAppendChar(pOut, '[');
+      if( j<iEnd ){
+        jsonAppendChar(pOut, '\n');
+        pPretty->nIndent++;
+        while( pOut->eErr==0 ){
+          jsonPrettyIndent(pPretty);
+          j = jsonTranslateBlobToPrettyText(pPretty, j);
+          if( j>=iEnd ) break;
+          jsonAppendRawNZ(pOut, ",\n", 2);
+        }
+        jsonAppendChar(pOut, '\n');
+        pPretty->nIndent--;
+        jsonPrettyIndent(pPretty);
+      }
+      jsonAppendChar(pOut, ']');
+      i = iEnd;
+      break;
+    }
+    case JSONB_OBJECT: {
+      j = i+n;
+      iEnd = j+sz;
+      jsonAppendChar(pOut, '{');
+      if( j<iEnd ){
+        jsonAppendChar(pOut, '\n');
+        pPretty->nIndent++;
+        while( pOut->eErr==0 ){
+          jsonPrettyIndent(pPretty);
+          j = jsonTranslateBlobToText(pParse, j, pOut);
+          if( j>iEnd ){
+            pOut->eErr |= JSTRING_MALFORMED;
+            break;
+          }
+          jsonAppendRawNZ(pOut, ": ", 2);
+          j = jsonTranslateBlobToPrettyText(pPretty, j);
+          if( j>=iEnd ) break;
+          jsonAppendRawNZ(pOut, ",\n", 2);
+        }
+        jsonAppendChar(pOut, '\n');
+        pPretty->nIndent--;
+        jsonPrettyIndent(pPretty);
+      }
+      jsonAppendChar(pOut, '}');
+      i = iEnd;
+      break;
+    }
+    default: {
+      i = jsonTranslateBlobToText(pParse, i, pOut);
+      break;
+    }
+  }
+  return i;
+}
+
+
 /* Return true if the input pJson
 **
 ** For performance reasons, this routine does not do a detailed check of the
@@ -4255,6 +4360,40 @@ json_type_done:
   jsonParseFree(p);
 }
 
+/*
+** json_pretty(JSON)
+** json_pretty(JSON, INDENT)
+**
+** Return text that is a pretty-printed rendering of the input JSON.
+** If the argument is not valid JSON, return NULL.
+**
+** The INDENT argument is text that is used for indentation.  If omitted,
+** it defaults to four spaces (the same as PostgreSQL).
+*/
+static void jsonPrettyFunc(
+  sqlite3_context *ctx,
+  int argc,
+  sqlite3_value **argv
+){
+  JsonString s;          /* The output string */
+  JsonPretty x;          /* Pretty printing context */
+
+  memset(&x, 0, sizeof(x));
+  x.pParse = jsonParseFuncArg(ctx, argv[0], 0);
+  if( x.pParse==0 ) return;
+  x.pOut = &s;
+  jsonStringInit(&s, ctx);
+  if( argc==1 || (x.zIndent = (const char*)sqlite3_value_text(argv[1]))==0 ){
+    x.zIndent = "    ";
+    x.szIndent = 4;
+  }else{
+    x.szIndent = (u32)strlen(x.zIndent);
+  }
+  jsonTranslateBlobToPrettyText(&x, 0);
+  jsonReturnString(&s, 0, 0);
+  jsonParseFree(x.pParse);
+}
+
 /*
 ** json_valid(JSON)
 ** json_valid(JSON, FLAGS)
@@ -5269,6 +5408,8 @@ void sqlite3RegisterJsonFunctions(void){
     JFUNCTION(jsonb_object,      -1,0,1, 1,1,0,          jsonObjectFunc),
     JFUNCTION(json_patch,         2,1,1, 0,0,0,          jsonPatchFunc),
     JFUNCTION(jsonb_patch,        2,1,0, 0,1,0,          jsonPatchFunc),
+    JFUNCTION(json_pretty,        1,1,0, 0,0,0,          jsonPrettyFunc),
+    JFUNCTION(json_pretty,        2,1,0, 0,0,0,          jsonPrettyFunc),
     JFUNCTION(json_quote,         1,0,1, 1,0,0,          jsonQuoteFunc),
     JFUNCTION(json_remove,       -1,1,1, 0,0,0,          jsonRemoveFunc),
     JFUNCTION(jsonb_remove,      -1,1,0, 0,1,0,          jsonRemoveFunc),