From 2b87c45ba6f8950ffc44cb6a3c861ad2e5f176a8 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Mon, 26 Feb 2007 14:55:56 -0500 Subject: [PATCH] sha1_file.c: cleanup "offset" usage First there are too many offsets there and it is getting confusing. So 'offset' is now 'curpos' to distinguish from other offsets like 'obj_offset'. Then structures like x = foo(x, &y) are now done as y = foo(&x). It looks more natural that the result y be returned directly and x be passed as reference to be updated in place. This has the effect of reducing some line length and removing a few, needing a bit less stack space, and it even reduces the compiled code size. Signed-off-by: Nicolas Pitre Signed-off-by: Junio C Hamano --- sha1_file.c | 110 ++++++++++++++++++++++++---------------------------- 1 file changed, 51 insertions(+), 59 deletions(-) diff --git a/sha1_file.c b/sha1_file.c index 57a9b532cf..8147a4f505 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -1043,12 +1043,11 @@ void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned l static unsigned long get_delta_base(struct packed_git *p, struct pack_window **w_curs, - unsigned long offset, + unsigned long *curpos, enum object_type kind, - unsigned long delta_obj_offset, - unsigned long *base_obj_offset) + unsigned long delta_obj_offset) { - unsigned char *base_info = use_pack(p, w_curs, offset, NULL); + unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL); unsigned long base_offset; /* use_pack() assured us we have [base_info, base_info + 20) @@ -1071,18 +1070,17 @@ static unsigned long get_delta_base(struct packed_git *p, base_offset = delta_obj_offset - base_offset; if (base_offset >= delta_obj_offset) die("delta base offset out of bound"); - offset += used; + *curpos += used; } else if (kind == OBJ_REF_DELTA) { /* The base entry _must_ be in the same pack */ base_offset = find_pack_entry_one(base_info, p); if (!base_offset) die("failed to find delta-pack base object %s", sha1_to_hex(base_info)); - offset += 20; + *curpos += 20; } else die("I am totally screwed"); - *base_obj_offset = base_offset; - return offset; + return base_offset; } /* forward declaration for a mutually recursive function */ @@ -1091,7 +1089,7 @@ static int packed_object_info(struct packed_git *p, unsigned long offset, static int packed_delta_info(struct packed_git *p, struct pack_window **w_curs, - unsigned long offset, + unsigned long curpos, enum object_type kind, unsigned long obj_offset, char *type, @@ -1099,8 +1097,7 @@ static int packed_delta_info(struct packed_git *p, { unsigned long base_offset; - offset = get_delta_base(p, w_curs, offset, kind, - obj_offset, &base_offset); + base_offset = get_delta_base(p, w_curs, &curpos, kind, obj_offset); /* We choose to only get the type of the base object and * ignore potentially corrupt pack file that expects the delta @@ -1113,7 +1110,6 @@ static int packed_delta_info(struct packed_git *p, if (sizep) { const unsigned char *data; unsigned char delta_head[20], *in; - unsigned long result_size; z_stream stream; int st; @@ -1123,10 +1119,10 @@ static int packed_delta_info(struct packed_git *p, inflateInit(&stream); do { - in = use_pack(p, w_curs, offset, &stream.avail_in); + in = use_pack(p, w_curs, curpos, &stream.avail_in); stream.next_in = in; st = inflate(&stream, Z_FINISH); - offset += stream.next_in - in; + curpos += stream.next_in - in; } while ((st == Z_OK || st == Z_BUF_ERROR) && stream.total_out < sizeof(delta_head)); inflateEnd(&stream); @@ -1143,21 +1139,20 @@ static int packed_delta_info(struct packed_git *p, get_delta_hdr_size(&data, delta_head+sizeof(delta_head)); /* Read the result size */ - result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head)); - *sizep = result_size; + *sizep = get_delta_hdr_size(&data, delta_head+sizeof(delta_head)); } return 0; } -static unsigned long unpack_object_header(struct packed_git *p, - struct pack_window **w_curs, - unsigned long offset, - enum object_type *type, - unsigned long *sizep) +static int unpack_object_header(struct packed_git *p, + struct pack_window **w_curs, + unsigned long *curpos, + unsigned long *sizep) { unsigned char *base; unsigned int left; unsigned long used; + enum object_type type; /* use_pack() assures us we have [base, base + 20) available * as a range that we can look at at. (Its actually the hash @@ -1165,16 +1160,17 @@ static unsigned long unpack_object_header(struct packed_git *p, * the maximum deflated object size is 2^137, which is just * insane, so we know won't exceed what we have been given. */ - base = use_pack(p, w_curs, offset, &left); - used = unpack_object_header_gently(base, left, type, sizep); + base = use_pack(p, w_curs, *curpos, &left); + used = unpack_object_header_gently(base, left, &type, sizep); if (!used) die("object offset outside of pack file"); + *curpos += used; - return offset + used; + return type; } void packed_object_info_detail(struct packed_git *p, - unsigned long offset, + unsigned long obj_offset, char *type, unsigned long *size, unsigned long *store_size, @@ -1182,13 +1178,13 @@ void packed_object_info_detail(struct packed_git *p, unsigned char *base_sha1) { struct pack_window *w_curs = NULL; - unsigned long obj_offset, val; + unsigned long curpos, dummy; unsigned char *next_sha1; enum object_type kind; *delta_chain_length = 0; - obj_offset = offset; - offset = unpack_object_header(p, &w_curs, offset, &kind, size); + curpos = obj_offset; + kind = unpack_object_header(p, &w_curs, &curpos, size); for (;;) { switch (kind) { @@ -1204,61 +1200,58 @@ void packed_object_info_detail(struct packed_git *p, unuse_pack(&w_curs); return; case OBJ_OFS_DELTA: - get_delta_base(p, &w_curs, offset, kind, - obj_offset, &offset); + obj_offset = get_delta_base(p, &w_curs, &curpos, kind, obj_offset); if (*delta_chain_length == 0) { - /* TODO: find base_sha1 as pointed by offset */ + /* TODO: find base_sha1 as pointed by curpos */ } break; case OBJ_REF_DELTA: - next_sha1 = use_pack(p, &w_curs, offset, NULL); + next_sha1 = use_pack(p, &w_curs, curpos, NULL); if (*delta_chain_length == 0) hashcpy(base_sha1, next_sha1); - offset = find_pack_entry_one(next_sha1, p); + obj_offset = find_pack_entry_one(next_sha1, p); break; } - obj_offset = offset; - offset = unpack_object_header(p, &w_curs, offset, &kind, &val); (*delta_chain_length)++; + curpos = obj_offset; + kind = unpack_object_header(p, &w_curs, &curpos, &dummy); } } -static int packed_object_info(struct packed_git *p, unsigned long offset, +static int packed_object_info(struct packed_git *p, unsigned long obj_offset, char *type, unsigned long *sizep) { struct pack_window *w_curs = NULL; - unsigned long size, obj_offset = offset; + unsigned long size, curpos = obj_offset; enum object_type kind; - int r; - offset = unpack_object_header(p, &w_curs, offset, &kind, &size); + kind = unpack_object_header(p, &w_curs, &curpos, &size); switch (kind) { case OBJ_OFS_DELTA: case OBJ_REF_DELTA: - r = packed_delta_info(p, &w_curs, offset, kind, - obj_offset, type, sizep); - unuse_pack(&w_curs); - return r; + packed_delta_info(p, &w_curs, curpos, kind, + obj_offset, type, sizep); + break; case OBJ_COMMIT: case OBJ_TREE: case OBJ_BLOB: case OBJ_TAG: strcpy(type, type_names[kind]); - unuse_pack(&w_curs); + if (sizep) + *sizep = size; break; default: die("pack %s contains unknown object type %d", p->pack_name, kind); } - if (sizep) - *sizep = size; + unuse_pack(&w_curs); return 0; } static void *unpack_compressed_entry(struct packed_git *p, struct pack_window **w_curs, - unsigned long offset, + unsigned long curpos, unsigned long size) { int st; @@ -1273,10 +1266,10 @@ static void *unpack_compressed_entry(struct packed_git *p, inflateInit(&stream); do { - in = use_pack(p, w_curs, offset, &stream.avail_in); + in = use_pack(p, w_curs, curpos, &stream.avail_in); stream.next_in = in; st = inflate(&stream, Z_FINISH); - offset += stream.next_in - in; + curpos += stream.next_in - in; } while (st == Z_OK || st == Z_BUF_ERROR); inflateEnd(&stream); if ((st != Z_STREAM_END) || stream.total_out != size) { @@ -1289,7 +1282,7 @@ static void *unpack_compressed_entry(struct packed_git *p, static void *unpack_delta_entry(struct packed_git *p, struct pack_window **w_curs, - unsigned long offset, + unsigned long curpos, unsigned long delta_size, enum object_type kind, unsigned long obj_offset, @@ -1299,14 +1292,13 @@ static void *unpack_delta_entry(struct packed_git *p, void *delta_data, *result, *base; unsigned long result_size, base_size, base_offset; - offset = get_delta_base(p, w_curs, offset, kind, - obj_offset, &base_offset); + base_offset = get_delta_base(p, w_curs, &curpos, kind, obj_offset); base = unpack_entry(p, base_offset, type, &base_size); if (!base) die("failed to read delta base object at %lu from %s", base_offset, p->pack_name); - delta_data = unpack_compressed_entry(p, w_curs, offset, delta_size); + delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size); result = patch_delta(base, base_size, delta_data, delta_size, &result_size); @@ -1318,19 +1310,19 @@ static void *unpack_delta_entry(struct packed_git *p, return result; } -void *unpack_entry(struct packed_git *p, unsigned long offset, - char *type, unsigned long *sizep) +void *unpack_entry(struct packed_git *p, unsigned long obj_offset, + char *type, unsigned long *sizep) { struct pack_window *w_curs = NULL; - unsigned long size, obj_offset = offset; + unsigned long size, curpos = obj_offset; enum object_type kind; void *retval; - offset = unpack_object_header(p, &w_curs, offset, &kind, &size); + kind = unpack_object_header(p, &w_curs, &curpos, &size); switch (kind) { case OBJ_OFS_DELTA: case OBJ_REF_DELTA: - retval = unpack_delta_entry(p, &w_curs, offset, size, + retval = unpack_delta_entry(p, &w_curs, curpos, size, kind, obj_offset, type, sizep); break; case OBJ_COMMIT: @@ -1339,7 +1331,7 @@ void *unpack_entry(struct packed_git *p, unsigned long offset, case OBJ_TAG: strcpy(type, type_names[kind]); *sizep = size; - retval = unpack_compressed_entry(p, &w_curs, offset, size); + retval = unpack_compressed_entry(p, &w_curs, curpos, size); break; default: die("unknown object type %i in %s", kind, p->pack_name);