Use name hashes in depends to avoid strcmp calls

Just like we did for package name comparsions, if we add a depend name_hash
field on depend struct initialization, we can use it instead of doing a
string name comparison, saving us a lot of checks in the depcmp code.

Signed-off-by: Dan McGee <dan@archlinux.org>

2 files changed, 18 insertions, 8 deletions

diff --git a/lib/libalpm/deps.c b/lib/libalpm/deps.c
index e37eb02e..2ed9d30a 100644
--- a/lib/libalpm/deps.c
+++ b/lib/libalpm/deps.c
@@ -322,15 +322,20 @@ static int dep_vercmp(const char *version1, pmdepmod_t mod,
 int _alpm_depcmp(pmpkg_t *pkg, pmdepend_t *dep)
 {
 	alpm_list_t *i;
-	const char *pkgname = alpm_pkg_get_name(pkg);
-	const char *pkgversion = alpm_pkg_get_version(pkg);
+	const char *pkgname = pkg->name;
+	const char *pkgversion = pkg->version;
 	int satisfy = 0;
 
 	/* check (pkg->name, pkg->version) */
-	satisfy = (strcmp(pkgname, dep->name) == 0
-			&& dep_vercmp(pkgversion, dep->mod, dep->version));
-	if(satisfy) {
-		return(satisfy);
+	if(pkg->name_hash && dep->name_hash
+			&& pkg->name_hash != dep->name_hash) {
+		/* skip more expensive checks */
+	} else {
+		satisfy = (strcmp(pkgname, dep->name) == 0
+				&& dep_vercmp(pkgversion, dep->mod, dep->version));
+		if(satisfy) {
+			return(satisfy);
+		}
 	}
 
 	/* check provisions, format : "name=version" */
@@ -380,7 +385,8 @@ pmdepend_t *_alpm_splitdep(const char *depstring)
 		depend->mod = PM_DEP_MOD_LE;
 		*ptr = '\0';
 		ptr += 2;
-	} else if((ptr = strstr(newstr, "="))) { /* Note: we must do =,<,> checks after <=, >= checks */
+	} else if((ptr = strstr(newstr, "="))) {
+		/* Note: we must do =,<,> checks after <=, >= checks */
 		depend->mod = PM_DEP_MOD_EQ;
 		*ptr = '\0';
 		ptr += 1;
@@ -396,6 +402,7 @@ pmdepend_t *_alpm_splitdep(const char *depstring)
 		/* no version specified - copy the name and return it */
 		depend->mod = PM_DEP_MOD_ANY;
 		STRDUP(depend->name, newstr, RET_ERR(PM_ERR_MEMORY, NULL));
+		depend->name_hash = _alpm_hash_sdbm(depend->name);
 		depend->version = NULL;
 		free(newstr);
 		return(depend);
@@ -404,6 +411,7 @@ pmdepend_t *_alpm_splitdep(const char *depstring)
 	/* if we get here, we have a version comparator, copy the right parts
 	 * to the right places */
 	STRDUP(depend->name, newstr, RET_ERR(PM_ERR_MEMORY, NULL));
+	depend->name_hash = _alpm_hash_sdbm(depend->name);
 	STRDUP(depend->version, ptr, RET_ERR(PM_ERR_MEMORY, NULL));
 	free(newstr);
 
@@ -416,6 +424,7 @@ pmdepend_t *_alpm_dep_dup(const pmdepend_t *dep)
 	CALLOC(newdep, 1, sizeof(pmdepend_t), RET_ERR(PM_ERR_MEMORY, NULL));
 
 	STRDUP(newdep->name, dep->name, RET_ERR(PM_ERR_MEMORY, NULL));
+	newdep->name_hash = dep->name_hash;
 	STRDUP(newdep->version, dep->version, RET_ERR(PM_ERR_MEMORY, NULL));
 	newdep->mod = dep->mod;
 
diff --git a/lib/libalpm/deps.h b/lib/libalpm/deps.h
index 6fa763e1..b720b364 100644
--- a/lib/libalpm/deps.h
+++ b/lib/libalpm/deps.h
@@ -29,9 +29,10 @@
 
 /* Dependency */
 struct __pmdepend_t {
-	pmdepmod_t mod;
 	char *name;
 	char *version;
+	long name_hash;
+	pmdepmod_t mod;
 };
 
 /* Missing dependency */