Move string hash function to librpmio and rename for namespacing

- There are places in rpmio and build that would benefit from hashing, but
  hashFunctionString() being internal to librpm has prevented that. Rename
  to rstrhash() to resemble the other foo in rpmstring.h for
  minimal namespacing as its now public function and update callers.
- Also mark the function as "pure" - it only looks at its arguments.
  This is one of the busiest functions in entire rpm so any optimization
  no matter how minor is well worth it.
- Hereby awarding hashFunctionString() with the grand prize for
  the Most Moved Around Function in rpm ;)

lib/Makefile.am

@@ -26,7 +26,7 @@ librpm_la_SOURCES = \
 	rpmdb.c rpmdb_internal.h \
 	fprint.c fprint.h tagname.c rpmtd.c \
 	cpio.c cpio.h depends.c order.c formats.c tagexts.c fsm.c fsm.h \
-	manifest.c manifest.h misc.c package.c \
+	manifest.c manifest.h package.c \
 	poptALL.c poptI.c poptQV.c psm.c query.c \
 	rpmal.c rpmal.h rpmchecksig.c rpmds.c rpmfi.c rpmfi_internal.h \
 	rpmgi.h rpmgi.c rpminstall.c rpmts_internal.h \

lib/depends.c

@@ -530,7 +530,7 @@ int rpmtsCheck(rpmts ts)
     }
 
     /* XXX FIXME: figure some kind of heuristic for the cache size */
-    dcache = depCacheCreate(5001, hashFunctionString, strcmp,
+    dcache = depCacheCreate(5001, rstrhash, strcmp,
 				     (depCacheFreeKey)rfree, NULL);
 
     /*

lib/fprint.c

@@ -29,7 +29,7 @@ fingerPrintCache fpCacheCreate(int sizeHint)
     fingerPrintCache fpc;
 
     fpc = xmalloc(sizeof(*fpc));
-    fpc->ht = rpmFpEntryHashCreate(sizeHint, hashFunctionString, strcmp,
+    fpc->ht = rpmFpEntryHashCreate(sizeHint, rstrhash, strcmp,
 				   (rpmFpEntryHashFreeKey)free,
 				   (rpmFpEntryHashFreeData)free);
     return fpc;
@@ -195,8 +195,8 @@ unsigned int fpHashFunction(const fingerPrint * fp)
     unsigned int hash = 0;
     int j;
 
-    hash = hashFunctionString(fp->baseName);
-    if (fp->subDir) hash ^= hashFunctionString(fp->subDir);
+    hash = rstrhash(fp->baseName);
+    if (fp->subDir) hash ^= rstrhash(fp->subDir);
 
     hash ^= ((unsigned)fp->entry->dev);
     for (j=0; j<4; j++) hash ^= ((fp->entry->ino >> (8*j)) & 0xFF) << ((3-j)*8);

lib/misc.c

@@ -1,24 +0,0 @@
-/**
- * \file lib/misc.c
- */
-
-#include "system.h"
-#include "lib/misc.h"
-#include "debug.h"
-
-unsigned int hashFunctionString(const char * string)
-{
-    /* Jenkins One-at-a-time hash */
-    unsigned int hash = 0xe4721b68;
-
-    while (*string != '\0') {
-      hash += *string;
-      hash += (hash << 10);
-      hash ^= (hash >> 6);
-      string++;
-    }
-    hash += (hash << 3);
-    hash ^= (hash >> 11);
-    hash += (hash << 15);
-    return hash;
-}

lib/misc.h

@@ -24,9 +24,6 @@ char * rpmVerifyString(uint32_t verifyResult, const char *pad);
 RPM_GNUC_INTERNAL
 char * rpmFFlagsString(uint32_t fflags, const char *pad);
 
-RPM_GNUC_INTERNAL
-unsigned int hashFunctionString(const char * string);
-
 typedef char * (*headerTagFormatFunction) (rpmtd td, char * formatPrefix);
 typedef int (*headerTagTagFunction) (Header h, rpmtd td, headerGetFlags hgflags);
 

lib/rpmal.c

@@ -121,7 +121,7 @@ rpmal rpmalFree(rpmal al)
 }
 
 static unsigned int fileHash(struct fileNameEntry_s file){
-    return hashFunctionString(file.dirName) ^ hashFunctionString(file.baseName);
+    return rstrhash(file.dirName) ^ rstrhash(file.baseName);
 }
 
 static int fileCompare(struct fileNameEntry_s one, struct fileNameEntry_s two) {
@@ -240,7 +240,7 @@ static void rpmalMakeIndex(rpmal al)
 	    fileCnt += rpmfiFC(alp->fi);
     }
 
-    al->providesHash = rpmalProvidesHashCreate(providesCnt/4+128, hashFunctionString,
+    al->providesHash = rpmalProvidesHashCreate(providesCnt/4+128, rstrhash,
 					       strcmp, NULL, NULL);
     al->fileHash = rpmalFileHashCreate(fileCnt/4+128, fileHash, fileCompare,
 				       NULL, NULL);

lib/rpmug.c

@@ -23,7 +23,7 @@ const char * rpmugStashStr(const char *str)
     const char *ret = NULL;
     if (str) {
 	if (strStash == NULL) {
-	    strStash = strCacheCreate(64, hashFunctionString, strcmp,
+	    strStash = strCacheCreate(64, rstrhash, strcmp,
 				      (strCacheFreeKey)rfree);
 	}
 	

lib/transaction.c

@@ -862,7 +862,7 @@ rpmdbMatchIterator rpmFindBaseNamesInDB(rpmts ts, uint64_t fileCount)
     const char * baseName;
 
     rpmStringSet baseNames = rpmStringSetCreate(fileCount, 
-					hashFunctionString, strcmp, NULL);
+					rstrhash, strcmp, NULL);
 
     mi = rpmdbNewIterator(rpmtsGetRdb(ts), RPMDBI_BASENAMES);
 

rpmio/rpmstring.c

@@ -189,3 +189,20 @@ size_t rstrlcpy(char *dest, const char *src, size_t n)
 
     return s - src - 1; /* count does not include NUL */
 }
+
+unsigned int rstrhash(const char * string)
+{
+    /* Jenkins One-at-a-time hash */
+    unsigned int hash = 0xe4721b68;
+
+    while (*string != '\0') {
+      hash += *string;
+      hash += (hash << 10);
+      hash ^= (hash >> 6);
+      string++;
+    }
+    hash += (hash << 3);
+    hash ^= (hash >> 11);
+    hash += (hash << 15);
+    return hash;
+}

rpmio/rpmstring.h

@@ -172,6 +172,14 @@ char *rstrscat(char **dest, const char *arg, ...) RPM_GNUC_NULL_TERMINATED;
  */
 size_t rstrlcpy(char *dest, const char *src, size_t n);
 
+/** \ingroup rpmstring
+ * String hashing function
+ * @param string	string to hash
+ * @return		hash id
+ */
+RPM_GNUC_PURE
+unsigned int rstrhash(const char * string);
+
 #ifdef __cplusplus
 }
 #endif