[PATCH v2 1/2] read-cache: factor out get_sha1_from_index() helper

[tboegi]

From: Torsten Bögershausen <tbo...@web.de>

Factor out the retrieval of the sha1 for a given path in
read_blob_data_from_index() into the function get_sha1_from_index().

This will be used in the next commit, when convert.c can do the
analyze for "text=auto" without slurping the whole blob into memory
at once.

Add a wrapper definition get_sha1_from_cache().

Signed-off-by: Torsten Bögershausen <tbo...@web.de>
---
 cache.h      |  3 +++
 read-cache.c | 29 ++++++++++++++++++-----------
 2 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/cache.h b/cache.h
index 1604e29..04de209 100644
--- a/cache.h
+++ b/cache.h
@@ -380,6 +380,7 @@ extern void free_name_hash(struct index_state *istate);
 #define unmerge_cache_entry_at(at) unmerge_index_entry_at(&the_index, at)
 #define unmerge_cache(pathspec) unmerge_index(&the_index, pathspec)
 #define read_blob_data_from_cache(path, sz) 
read_blob_data_from_index(&the_index, (path), (sz))
+#define get_sha1_from_cache(path)  get_sha1_from_index (&the_index, (path))
 #endif
 
 enum object_type {
@@ -1089,6 +1090,8 @@ static inline void *read_sha1_file(const unsigned char 
*sha1, enum object_type *
        return read_sha1_file_extended(sha1, type, size, LOOKUP_REPLACE_OBJECT);
 }
 
+const unsigned char *get_sha1_from_index(struct index_state *istate, const 
char *path);
+
 /*
  * This internal function is only declared here for the benefit of
  * lookup_replace_object().  Please do not call it directly.
diff --git a/read-cache.c b/read-cache.c
index 38d67fa..5a1df14 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -2290,13 +2290,27 @@ int index_name_is_other(const struct index_state 
*istate, const char *name,
 
 void *read_blob_data_from_index(struct index_state *istate, const char *path, 
unsigned long *size)
 {
-       int pos, len;
+       const unsigned char *sha1;
        unsigned long sz;
        enum object_type type;
        void *data;
 
-       len = strlen(path);
-       pos = index_name_pos(istate, path, len);
+       sha1 = get_sha1_from_index(istate, path);
+       if (!sha1)
+               return NULL;
+       data = read_sha1_file(sha1, &type, &sz);
+       if (!data || type != OBJ_BLOB) {
+               free(data);
+               return NULL;
+       }
+       if (size)
+               *size = sz;
+       return data;
+}
+
+const unsigned char *get_sha1_from_index(struct index_state *istate, const 
char *path)
+{
+       int pos = index_name_pos(istate, path, strlen(path));
        if (pos < 0) {
                /*
                 * We might be in the middle of a merge, in which
@@ -2312,14 +2326,7 @@ void *read_blob_data_from_index(struct index_state 
*istate, const char *path, un
        }
        if (pos < 0)
                return NULL;
-       data = read_sha1_file(istate->cache[pos]->oid.hash, &type, &sz);
-       if (!data || type != OBJ_BLOB) {
-               free(data);
-               return NULL;
-       }
-       if (size)
-               *size = sz;
-       return data;
+       return istate->cache[pos]->oid.hash;
 }
 
 void stat_validity_clear(struct stat_validity *sv)
-- 
2.10.0