Faster text decoder for kv_os.c.

FossilOrigin-Name: 3354a2edb762d70ccc31d4d25f81b70e644d76e01cb1e81d2e97b5414d809d30

manifest

@@ -1,5 +1,5 @@
-C Fix\suninitialized\svariable\sin\srollback-journal\sprocessing\sin\sos_kv.c
-D 2022-09-12T15:59:35.676
+C Faster\stext\sdecoder\sfor\skv_os.c.
+D 2022-09-12T17:44:35.983
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -574,7 +574,7 @@ 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 2b4c04a470c05fe95a84d2ba3a5eb4874f0dbaa12da3a47f221ee3beec7eeda0
+F src/os_kv.c 3f4c2f56375d50b210ddadfbfd652001c63e8b8138b8b2c9339e32d610107558
 F src/os_setup.h 0711dbc4678f3ac52d7fe736951b6384a0615387c4ba5135a4764e4e31f4b6a6
 F src/os_unix.c d6322b78130d995160bb9cfb7850678ad6838b08c1d13915461b33326a406c04
 F src/os_win.c e9454cb141908e8eef2102180bad353a36480612d5b736e4c2bd5777d9b25a34
@@ -2004,8 +2004,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 250a935aeb94d3fadec0d3fe22de85de4e658e2fdb3be3aa9a8bbc8f7b7d8414
-R b0d44b8764d44e0d25567b7049186ee6
+P e49682c5eac91958f143e639c5656ca54560d14f5805d514bf4aa0c206e63844
+R 81ed8ce798a46ae2544ed3d032a07983
 U drh
-Z b805cc7ee3bf0477637e784d78058472
+Z 85de880a922a0287811e4245e97cc473
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-e49682c5eac91958f143e639c5656ca54560d14f5805d514bf4aa0c206e63844
+3354a2edb762d70ccc31d4d25f81b70e644d76e01cb1e81d2e97b5414d809d30

src/os_kv.c

@@ -527,12 +527,25 @@ static int kvvfsEncode(const char *aData, int nData, char *aOut){
   return j;
 }
 
-/* Convert hex to binary */
-static char kvvfsHexToBinary(char c){
-  if( c>='0' && c<='9' ) return c - '0';
-  if( c>='A' && c<='F' ) return c - 'A' + 10;
-  return 0;
-}
+static const signed char kvvfsHexValue[256] = {
+  -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+   0,  1,  2,  3,  4,  5,  6,  7,    8,  9, -1, -1, -1, -1, -1, -1,
+  -1, 10, 11, 12, 13, 14, 15, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+
+  -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,   -1, -1, -1, -1, -1, -1, -1, -1
+};
 
 /*
 ** Decode the text encoding back to binary.  The binary content is
@@ -540,28 +553,35 @@ static char kvvfsHexToBinary(char c){
 **
 ** The return value is the number of bytes actually written into aOut[].
 */
-static int kvvfsDecode(const char *aIn, char *aOut, int nOut){
+static int kvvfsDecode(const char *a, char *aOut, int nOut){
   int i, j;
   int c;
+  const unsigned char *aIn = (const unsigned char*)a;
   i = 0;
   j = 0;
-  while( (c = aIn[i])!=0 ){
-    if( c>='a' ){
+  while( 1 ){
+    c = kvvfsHexValue[aIn[i]];
+    if( c<0 ){
       int n = 0;
       int mult = 1;
+      c = aIn[i];
+      if( c==0 ) break;
       while( c>='a' && c<='z' ){
         n += (c - 'a')*mult;
         mult *= 26;
         c = aIn[++i];
       }
       if( j+n>nOut ) return -1;
-      while( n-->0 ){
-        aOut[j++] = 0;
-      }
+      memset(&aOut[j], 0, n);
+      j += n;
+      c = aIn[i];
+      if( c==0 ) break;
     }else{
-      if( j>nOut ) return -1;
-      aOut[j] = kvvfsHexToBinary(aIn[i++])<<4;
-      aOut[j++] += kvvfsHexToBinary(aIn[i++]);
+      aOut[j] = c<<4;
+      c = kvvfsHexValue[aIn[++i]];
+      if( c<0 ) break;
+      aOut[j++] += c;
+      i++;
     }
   }
   return j;
@@ -1021,7 +1041,10 @@ static int kvvfsFullPathname(
   int nOut, 
   char *zOut
 ){
-  size_t nPath = strlen(zPath);
+  size_t nPath;
+
+zPath = "local";
+  nPath = strlen(zPath);
   SQLITE_KV_LOG(("xFullPathname(\"%s\")\n", zPath));
   if( nOut<nPath+1 ) nPath = nOut - 1;
   memcpy(zOut, zPath, nPath);