write_entry: avoid reading blobs in CE_RETRY case

When retrying a delayed filter-process request, we don't
need to send the blob to the filter a second time. However,
we read it unconditionally into a buffer, only to later
throw away that buffer. We can make this more efficient by
skipping the read in the first place when it isn't
necessary.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/entry.c b/entry.c
index 637c5958b0a90554378a461d69df18c1ceab4ff6..bec51e37a2c162456217b3a7f52e44edbb0eabb0 100644 (file)
--- a/entry.c
+++ b/entry.c
@@ -240,6 +240,7 @@ static int write_entry(struct cache_entry *ce,
                       char *path, const struct checkout *state, int to_tempfile)
 {
        unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;
+       struct delayed_checkout *dco = state->delayed_checkout;
        int fd, ret, fstat_done = 0;
        char *new;
        struct strbuf buf = STRBUF_INIT;
@@ -261,10 +262,19 @@ static int write_entry(struct cache_entry *ce,
        switch (ce_mode_s_ifmt) {
        case S_IFREG:
        case S_IFLNK:
-               new = read_blob_entry(ce, &size);
-               if (!new)
-                       return error("unable to read sha1 file of %s (%s)",
-                               path, oid_to_hex(&ce->oid));
+               /*
+                * We do not send the blob in case of a retry, so do not
+                * bother reading it at all.
+                */
+               if (ce_mode_s_ifmt == S_IFREG && dco && dco->state == CE_RETRY) {
+                       new = NULL;
+                       size = 0;
+               } else {
+                       new = read_blob_entry(ce, &size);
+                       if (!new)
+                               return error("unable to read sha1 file of %s (%s)",
+                                            path, oid_to_hex(&ce->oid));
+               }
 
                if (ce_mode_s_ifmt == S_IFLNK && has_symlinks && !to_tempfile) {
                        ret = symlink(new, path);
@@ -279,14 +289,7 @@ static int write_entry(struct cache_entry *ce,
                 * Convert from git internal format to working tree format
                 */
                if (ce_mode_s_ifmt == S_IFREG) {
-                       struct delayed_checkout *dco = state->delayed_checkout;
                        if (dco && dco->state != CE_NO_DELAY) {
-                               /* Do not send the blob in case of a retry. */
-                               if (dco->state == CE_RETRY) {
-                                       free(new);
-                                       new = NULL;
-                                       size = 0;
-                               }
                                ret = async_convert_to_working_tree(
                                        ce->name, new, size, &buf, dco);
                                if (ret && string_list_has_string(&dco->paths, ce->name)) {