Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(2)

Unified Diff: third_party/sqlite/src/src/hash.c

Issue 949043002: Add //third_party/sqlite to dirs_to_snapshot, remove net_sql.patch (Closed) Base URL: git@github.com:domokit/mojo.git@master
Patch Set: Created 5 years, 10 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « third_party/sqlite/src/src/hash.h ('k') | third_party/sqlite/src/src/insert.c » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: third_party/sqlite/src/src/hash.c
diff --git a/third_party/sqlite/src/src/hash.c b/third_party/sqlite/src/src/hash.c
index d4daf92a6ff30625cdbfca484dc84d755d6de6e9..b5886e064152b8face140874a447ec596c11832d 100644
--- a/third_party/sqlite/src/src/hash.c
+++ b/third_party/sqlite/src/src/hash.c
@@ -52,12 +52,11 @@ void sqlite3HashClear(Hash *pH){
/*
** The hashing function.
*/
-static unsigned int strHash(const char *z, int nKey){
- int h = 0;
- assert( nKey>=0 );
- while( nKey > 0 ){
- h = (h<<3) ^ h ^ sqlite3UpperToLower[(unsigned char)*z++];
- nKey--;
+static unsigned int strHash(const char *z){
+ unsigned int h = 0;
+ unsigned char c;
+ while( (c = (unsigned char)*z++)!=0 ){
+ h = (h<<3) ^ h ^ sqlite3UpperToLower[c];
}
return h;
}
@@ -113,7 +112,11 @@ static int rehash(Hash *pH, unsigned int new_size){
/* The inability to allocates space for a larger hash table is
** a performance hit but it is not a fatal error. So mark the
- ** allocation as a benign.
+ ** allocation as a benign. Use sqlite3Malloc()/memset(0) instead of
+ ** sqlite3MallocZero() to make the allocation, as sqlite3MallocZero()
+ ** only zeroes the requested number of bytes whereas this module will
+ ** use the actual amount of space allocated for the hash table (which
+ ** may be larger than the requested amount).
*/
sqlite3BeginBenignMalloc();
new_ht = (struct _ht *)sqlite3Malloc( new_size*sizeof(struct _ht) );
@@ -125,7 +128,7 @@ static int rehash(Hash *pH, unsigned int new_size){
pH->htsize = new_size = sqlite3MallocSize(new_ht)/sizeof(struct _ht);
memset(new_ht, 0, new_size*sizeof(struct _ht));
for(elem=pH->first, pH->first=0; elem; elem = next_elem){
- unsigned int h = strHash(elem->pKey, elem->nKey) % new_size;
+ unsigned int h = strHash(elem->pKey) % new_size;
next_elem = elem->next;
insertElement(pH, &new_ht[h], elem);
}
@@ -133,28 +136,33 @@ static int rehash(Hash *pH, unsigned int new_size){
}
/* This function (for internal use only) locates an element in an
-** hash table that matches the given key. The hash for this key has
-** already been computed and is passed as the 4th parameter.
+** hash table that matches the given key. The hash for this key is
+** also computed and returned in the *pH parameter.
*/
-static HashElem *findElementGivenHash(
+static HashElem *findElementWithHash(
const Hash *pH, /* The pH to be searched */
const char *pKey, /* The key we are searching for */
- int nKey, /* Bytes in key (not counting zero terminator) */
- unsigned int h /* The hash for this key. */
+ unsigned int *pHash /* Write the hash value here */
){
HashElem *elem; /* Used to loop thru the element list */
int count; /* Number of elements left to test */
+ unsigned int h; /* The computed hash */
if( pH->ht ){
- struct _ht *pEntry = &pH->ht[h];
+ struct _ht *pEntry;
+ h = strHash(pKey) % pH->htsize;
+ pEntry = &pH->ht[h];
elem = pEntry->chain;
count = pEntry->count;
}else{
+ h = 0;
elem = pH->first;
count = pH->count;
}
- while( count-- && ALWAYS(elem) ){
- if( elem->nKey==nKey && sqlite3StrNICmp(elem->pKey,pKey,nKey)==0 ){
+ *pHash = h;
+ while( count-- ){
+ assert( elem!=0 );
+ if( sqlite3StrICmp(elem->pKey,pKey)==0 ){
return elem;
}
elem = elem->next;
@@ -189,7 +197,7 @@ static void removeElementGivenHash(
}
sqlite3_free( elem );
pH->count--;
- if( pH->count<=0 ){
+ if( pH->count==0 ){
assert( pH->first==0 );
assert( pH->count==0 );
sqlite3HashClear(pH);
@@ -197,26 +205,20 @@ static void removeElementGivenHash(
}
/* Attempt to locate an element of the hash table pH with a key
-** that matches pKey,nKey. Return the data for this element if it is
+** that matches pKey. Return the data for this element if it is
** found, or NULL if there is no match.
*/
-void *sqlite3HashFind(const Hash *pH, const char *pKey, int nKey){
+void *sqlite3HashFind(const Hash *pH, const char *pKey){
HashElem *elem; /* The element that matches key */
unsigned int h; /* A hash on key */
assert( pH!=0 );
assert( pKey!=0 );
- assert( nKey>=0 );
- if( pH->ht ){
- h = strHash(pKey, nKey) % pH->htsize;
- }else{
- h = 0;
- }
- elem = findElementGivenHash(pH, pKey, nKey, h);
+ elem = findElementWithHash(pH, pKey, &h);
return elem ? elem->data : 0;
}
-/* Insert an element into the hash table pH. The key is pKey,nKey
+/* Insert an element into the hash table pH. The key is pKey
** and the data is "data".
**
** If no element exists with a matching key, then a new
@@ -230,20 +232,14 @@ void *sqlite3HashFind(const Hash *pH, const char *pKey, int nKey){
** If the "data" parameter to this function is NULL, then the
** element corresponding to "key" is removed from the hash table.
*/
-void *sqlite3HashInsert(Hash *pH, const char *pKey, int nKey, void *data){
+void *sqlite3HashInsert(Hash *pH, const char *pKey, void *data){
unsigned int h; /* the hash of the key modulo hash table size */
HashElem *elem; /* Used to loop thru the element list */
HashElem *new_elem; /* New element added to the pH */
assert( pH!=0 );
assert( pKey!=0 );
- assert( nKey>=0 );
- if( pH->htsize ){
- h = strHash(pKey, nKey) % pH->htsize;
- }else{
- h = 0;
- }
- elem = findElementGivenHash(pH,pKey,nKey,h);
+ elem = findElementWithHash(pH,pKey,&h);
if( elem ){
void *old_data = elem->data;
if( data==0 ){
@@ -251,7 +247,6 @@ void *sqlite3HashInsert(Hash *pH, const char *pKey, int nKey, void *data){
}else{
elem->data = data;
elem->pKey = pKey;
- assert(nKey==elem->nKey);
}
return old_data;
}
@@ -259,19 +254,14 @@ void *sqlite3HashInsert(Hash *pH, const char *pKey, int nKey, void *data){
new_elem = (HashElem*)sqlite3Malloc( sizeof(HashElem) );
if( new_elem==0 ) return data;
new_elem->pKey = pKey;
- new_elem->nKey = nKey;
new_elem->data = data;
pH->count++;
if( pH->count>=10 && pH->count > 2*pH->htsize ){
if( rehash(pH, pH->count*2) ){
assert( pH->htsize>0 );
- h = strHash(pKey, nKey) % pH->htsize;
+ h = strHash(pKey) % pH->htsize;
}
}
- if( pH->ht ){
- insertElement(pH, &pH->ht[h], new_elem);
- }else{
- insertElement(pH, 0, new_elem);
- }
+ insertElement(pH, pH->ht ? &pH->ht[h] : 0, new_elem);
return 0;
}
« no previous file with comments | « third_party/sqlite/src/src/hash.h ('k') | third_party/sqlite/src/src/insert.c » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698