From: drh <>
Date: Sat, 10 Sep 2022 18:38:21 +0000 (+0000)
Subject: Improved comments in os_kv.c.  Better names for the key/value name spaces.
X-Git-Tag: version-3.40.0~169^2~123^2~4
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c6c9c6aad0a8652d3daf0298fe9d411b03c79c41;p=thirdparty%2Fsqlite.git

Improved comments in os_kv.c.  Better names for the key/value name spaces.

FossilOrigin-Name: 8e1652a3856765c9146cc2a7e3b598a2dc7dc84c556b35eab9a35184514384b9
---

diff --git a/manifest b/manifest
index a139582803..23b98932b2 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Move\sthe\svfskv.c\sextension\sto\ssrc/os_kv.c\sand\smake\sit\spart\sof\sthe\samalgamation,\nactivated\sif\sand\sonly\sif\sSQLITE_OS_KV\sis\strue.
-D 2022-09-10T18:20:59.146
+C Improved\scomments\sin\sos_kv.c.\s\sBetter\snames\sfor\sthe\skey/value\sname\sspaces.
+D 2022-09-10T18:38:21.976
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -571,7 +571,7 @@ F src/notify.c 89a97dc854c3aa62ad5f384ef50c5a4a11d70fcc69f86de3e991573421130ed6
 F src/os.c 0eb831ba3575af5277e47f4edd14fdfc90025c67eb25ce5cda634518d308d4e9
 F src/os.h 1ff5ae51d339d0e30d8a9d814f4b8f8e448169304d83a7ed9db66a65732f3e63
 F src/os_common.h b2f4707a603e36811d9b1a13278bffd757857b85
-F src/os_kv.c dc409476c3e533def81d022849726f2892e69e6529d4a40a637224cfb3f5df68 w ext/misc/vfskv.c
+F src/os_kv.c c658ddfb433b982afb3d12d133117e8db9eee11af33db41c30a6f30375f9b99a
 F src/os_setup.h 0711dbc4678f3ac52d7fe736951b6384a0615387c4ba5135a4764e4e31f4b6a6
 F src/os_unix.c 102f7e5c5b59c18ea3dbc929dc3be8acb3afc0e0b6ad572e032335c9c27f44f1
 F src/os_win.c e9454cb141908e8eef2102180bad353a36480612d5b736e4c2bd5777d9b25a34
@@ -2001,8 +2001,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P c8e41279294ea7c2f041c7d4cbbd85fce47d55f2f56180ca837316f7dfd75237
-R 781601077fda92ceda7382ba24a16664
+P f6632e69c2ec1a7ddc4e51f3567e3bc082ee94a6dd51fdafdc0c3bf386a32d4c
+R 8cd4482ba17a8f6c143ea61b8462f46c
 U drh
-Z b2ad663d300b47ac24999ede7b88d1e7
+Z 81846bec91bdcab04bc60c9c032d039e
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 4bfd8ba9c2..c114a26d08 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-f6632e69c2ec1a7ddc4e51f3567e3bc082ee94a6dd51fdafdc0c3bf386a32d4c
\ No newline at end of file
+8e1652a3856765c9146cc2a7e3b598a2dc7dc84c556b35eab9a35184514384b9
\ No newline at end of file
diff --git a/src/os_kv.c b/src/os_kv.c
index 8ae1a65c59..1412de8122 100644
--- a/src/os_kv.c
+++ b/src/os_kv.c
@@ -165,26 +165,28 @@ static sqlite3_io_methods kvvfs_jrnl_io_methods = {
 
 /* Forward declarations for the low-level storage engine
 */
-#define KVSTORAGE_KEY_SZ  24
-#define KVSTORAGE_KEY_PREFIX  "kvvfs-"
+#define KVSTORAGE_KEY_SZ  32
 static int kvstorageWrite(const char*, const char *zKey, const char *zData);
 static int kvstorageDelete(const char*, const char *zKey);
 static int kvstorageRead(const char*, const char *zKey, char *zBuf, int nBuf);
 
 
 /* Expand the key name with an appropriate prefix and put the result
-** in pStore->zKey[]
+** zKeyOut[].  The zKeyOut[] buffer is assumed to hold at least
+** KVSTORAGE_KEY_SZ bytes.
 */
 static void kvstorageMakeKey(
   const char *zClass,
   const char *zKeyIn,
   char *zKeyOut
 ){
-  sqlite3_snprintf(KVSTORAGE_KEY_SZ, zKeyOut, "%s-%s", zClass, zKeyIn);
+  sqlite3_snprintf(KVSTORAGE_KEY_SZ, zKeyOut, "kvvfs-%s-%s", zClass, zKeyIn);
 }
 
-/* Write content into a key.  zKey is of limited size.  zData should be
-** pure text.  In other words, zData has already been encoded.
+/* Write content into a key.  zClass is the particular namespace of the
+** underlying key/value store to use - either "local" or "session".
+**
+** Both zKey and zData are zero-terminated pure text strings.
 **
 ** Return the number of errors.
 */
@@ -209,7 +211,9 @@ static int kvstorageWrite(
   }
 }
 
-/* Delete a key
+/* Delete a key (with its corresponding data) from the key/value
+** namespace given by zClass.  If the key does not previously exist,
+** this routine is a no-op.
 */
 static int kvstorageDelete(const char *zClass, const char *zKey){
   char zXKey[KVSTORAGE_KEY_SZ];
@@ -219,16 +223,17 @@ static int kvstorageDelete(const char *zClass, const char *zKey){
   return 0;
 }
 
-/* Read the value associated with a key and put the result in the first
+/* Read the value associated with a zKey from the key/value namespace given
+** by zClass and put the text data associated with that key in the first
 ** nBuf bytes of zBuf[].  The value might be truncated if zBuf is not large
-** enough to hold it all.  The value put into zBuf will always be zero
-** terminated.
+** enough to hold it all.  The value put into zBuf must always be zero
+** terminated, even if it gets truncated because nBuf is not large enough.
 **
 ** Return the total number of bytes in the data, without truncation, and
 ** not counting the final zero terminator.   Return -1 if the key does
 ** not exist.
 **
-** If nBuf==0 then this routine simply returns the size of the data without
+** If nBuf<=0 then this routine simply returns the size of the data without
 ** actually reading it.
 */
 static int kvstorageRead(
@@ -248,7 +253,7 @@ static int kvstorageRead(
     SQLITE_KV_TRACE(("KVVFS-READ   %-15s (-1)\n", zXKey));
     return -1;
   }
-  if( nBuf<0 ){
+  if( nBuf<=0 ){
     return (int)buf.st_size;
   }else if( nBuf==1 ){
     zBuf[0] = 0;
@@ -275,7 +280,6 @@ static int kvstorageRead(
 
 /****** Utility subroutines ************************************************/
 
-
 /*
 ** Encode binary into the text encoded used to persist on disk.
 ** The output text is stored in aOut[], which must be at least
@@ -446,7 +450,7 @@ static int kvvfsReadJrnl(
   assert( pFile->isJournal );
   SQLITE_KV_LOG(("xRead('%s-journal',%d,%lld)\n", pFile->zClass, iAmt, iOfst));
   if( pFile->aJrnl==0 ){
-    int szTxt = kvstorageRead(pFile->zClass, "jrnl", 0, -1);
+    int szTxt = kvstorageRead(pFile->zClass, "jrnl", 0, 0);
     char *aTxt;
     if( szTxt<=4 ){
       return SQLITE_IOERR;
@@ -752,9 +756,9 @@ static int kvvfsOpen(
     return SQLITE_CANTOPEN;
   }
   if( zName[0]=='s' ){
-    pFile->zClass = KVSTORAGE_KEY_PREFIX "ses";
+    pFile->zClass = "session";
   }else{
-    pFile->zClass = KVSTORAGE_KEY_PREFIX "loc";
+    pFile->zClass = "local";
   }
   pFile->aJrnl = 0;
   pFile->nJrnl = 0;
@@ -770,10 +774,10 @@ static int kvvfsOpen(
 */
 static int kvvfsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
   if( strcmp(zPath, "local-journal")==0 ){
-    kvstorageDelete(KVSTORAGE_KEY_PREFIX "loc", "jrnl");
+    kvstorageDelete("local", "jrnl");
   }else
   if( strcmp(zPath, "session-journal")==0 ){
-    kvstorageDelete(KVSTORAGE_KEY_PREFIX "ses", "jrnl");
+    kvstorageDelete("session", "jrnl");
   }
   return SQLITE_OK;
 }
@@ -790,16 +794,16 @@ static int kvvfsAccess(
 ){
   SQLITE_KV_LOG(("xAccess(\"%s\")\n", zPath));
   if( strcmp(zPath, "local-journal")==0 ){
-    *pResOut = kvstorageRead(KVSTORAGE_KEY_PREFIX "loc", "jrnl", 0, -1)>0;
+    *pResOut = kvstorageRead("local", "jrnl", 0, 0)>0;
   }else
   if( strcmp(zPath, "session-journal")==0 ){
-    *pResOut = kvstorageRead(KVSTORAGE_KEY_PREFIX "ses", "jrnl", 0, -1)>0;
+    *pResOut = kvstorageRead("session", "jrnl", 0, 0)>0;
   }else
   if( strcmp(zPath, "local")==0 ){
-    *pResOut = kvstorageRead(KVSTORAGE_KEY_PREFIX "loc", "sz", 0, -1)>0;
+    *pResOut = kvstorageRead("local", "sz", 0, 0)>0;
   }else
   if( strcmp(zPath, "session")==0 ){
-    *pResOut = kvstorageRead(KVSTORAGE_KEY_PREFIX "ses", "sz", 0, -1)>0;
+    *pResOut = kvstorageRead("session", "sz", 0, 0)>0;
   }else
   {
     *pResOut = 0;