From: David Barr Date: Mon, 21 Mar 2011 01:26:15 GMT Subject: [PATCH 1/3] vcs-svn: implement perfect hash for node-prop keys Message-ID: <1300670777-17197-1-git-send-email-david.barr@cordelta.com> In-Reply-To: <20110319085138.GB6706@elie> This eliminates one more dependency on string_pool. Signed-off-by: David Barr Signed-off-by: Jonathan Nieder Signed-off-by: David Barr Reviewed-by: Jonathan Nieder Signed-off-by: David Barr --- vcs-svn/svndump.c | 64 +++++++++++++++++++++++++++++++++++++--------------- 1 files changed, 45 insertions(+), 19 deletions(-) diff --git a/vcs-svn/svndump.c b/vcs-svn/svndump.c index 15b173e..48848ff 100644 --- a/vcs-svn/svndump.c +++ b/vcs-svn/svndump.c @@ -52,8 +52,7 @@ static struct { } dump_ctx; static struct { - uint32_t svn_log, svn_author, svn_date, svn_executable, svn_special, uuid, - revision_number, node_path, node_kind, node_action, + uint32_t uuid, revision_number, node_path, node_kind, node_action, node_copyfrom_path, node_copyfrom_rev, text_content_length, prop_content_length, content_length, svn_fs_dump_format_version, /* version 3 format */ @@ -92,11 +91,6 @@ static void reset_dump_ctx(uint32_t url) static void init_keys(void) { - keys.svn_log = pool_intern("svn:log"); - keys.svn_author = pool_intern("svn:author"); - keys.svn_date = pool_intern("svn:date"); - keys.svn_executable = pool_intern("svn:executable"); - keys.svn_special = pool_intern("svn:special"); keys.uuid = pool_intern("UUID"); keys.revision_number = pool_intern("Revision-number"); keys.node_path = pool_intern("Node-path"); @@ -113,22 +107,43 @@ static void init_keys(void) keys.prop_delta = pool_intern("Prop-delta"); } -static void handle_property(uint32_t key, const char *val, uint32_t len, +/* Compare string to literal of equal length; must be guarded by length test. */ +#define constcmp(s, ref) memcmp((s), (ref), sizeof(ref) - 1) + +static void handle_property(const char *key, const int sizeof_key, + const char *val, uint32_t len, uint32_t *type_set) { - if (key == keys.svn_log) { + switch (sizeof_key) { + case sizeof("svn:log"): + if (constcmp(key, "svn:log")) + break; if (!val) die("invalid dump: unsets svn:log"); /* Value length excludes terminating nul. */ strbuf_add(&rev_ctx.log, val, len + 1); - } else if (key == keys.svn_author) { + break; + case sizeof("svn:author"): + if (constcmp(key, "svn:author")) + break; rev_ctx.author = pool_intern(val); - } else if (key == keys.svn_date) { + break; + case sizeof("svn:date"): + if (constcmp(key, "svn:date")) + break; if (!val) die("invalid dump: unsets svn:date"); if (parse_date_basic(val, &rev_ctx.timestamp, NULL)) warning("invalid timestamp: %s", val); - } else if (key == keys.svn_executable || key == keys.svn_special) { + break; + case sizeof("svn:executable"): + case sizeof("svn:special"): + if (sizeof_key == sizeof("svn:executable") && + constcmp(key, "svn:executable")) + break; + if (sizeof_key == sizeof("svn:special") && + constcmp(key, "svn:special")) + break; if (*type_set) { if (!val) return; @@ -139,7 +154,7 @@ static void handle_property(uint32_t key, const char *val, uint32_t len, return; } *type_set = 1; - node_ctx.type = key == keys.svn_executable ? + node_ctx.type = sizeof_key == sizeof("svn:executable") ? REPO_MODE_EXE : REPO_MODE_LNK; } @@ -147,7 +162,9 @@ static void handle_property(uint32_t key, const char *val, uint32_t len, static void read_props(void) { - uint32_t key = ~0; + /* Reserve enough space for the longest standard key. */ + char key[sizeof("svn:executable")] = {0}; + int sizeof_key = 1; const char *t; /* * NEEDSWORK: to support simple mode changes like @@ -175,16 +192,25 @@ static void read_props(void) switch (type) { case 'K': - key = pool_intern(val); - continue; case 'D': - key = pool_intern(val); + if (len < sizeof(key) && val) { + memcpy(key, val, len + 1); + sizeof_key = len + 1; + } else { + /* nonstandard key. */ + *key = '\0'; + sizeof_key = 1; + } + if (type == 'K') + continue; + assert(type == 'D'); val = NULL; len = 0; /* fall through */ case 'V': - handle_property(key, val, len, &type_set); - key = ~0; + handle_property(key, sizeof_key, val, len, &type_set); + *key = '\0'; + sizeof_key = 1; continue; default: die("invalid property line: %s\n", t); -- 1.7.3.2.846.gf4b062