streaming.c: move {open,close,read} from vtable to "struct git_istream"
Move the definition of the structure around the open/close/read functions introduced in 46bf043807c (streaming: a new API to read from the object store, 2011-05-11) to instead populate "close" and "read" members in the "struct git_istream". This gets us rid of an extra pointer deference, and I think makes more sense. The "close" and "read" functions are the primary interface to the stream itself. Let's also populate a "open" callback in the same struct. That's now used by open_istream() after istream_source() decides what "open" function should be used. This isn't needed to get rid of the "stream_vtbl" variables, but makes sense for consistency. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Ævar Arnfjörð Bjarmason committed
May 5, 2021 at 14:33 UTC
d4e2d15a8b028352df480e7be9f1864f59c16299
1 file changed
+29
-43
streaming.c
+29
-43
@@ -15,11 +15,6 @@ typedef int (*open_istream_fn)(struct git_istream *,
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typedef int (*close_istream_fn)(struct git_istream *);
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typedef ssize_t (*read_istream_fn)(struct git_istream *, char *, size_t);
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-struct stream_vtbl {
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- close_istream_fn close;
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- read_istream_fn read;
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-};
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-
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#define FILTER_BUFFER (1024*16)
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struct filtered_istream {
@@ -33,7 +28,10 @@ struct filtered_istream {
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};
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struct git_istream {
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- const struct stream_vtbl *vtbl;
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+ open_istream_fn open;
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+ close_istream_fn close;
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+ read_istream_fn read;
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+
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unsigned long size; /* inflated size of full object */
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git_zstream z;
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enum { z_unused, z_used, z_done, z_error } z_state;
@@ -146,18 +144,14 @@ static ssize_t read_istream_filtered(struct git_istream *st, char *buf,
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return filled;
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}
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-static struct stream_vtbl filtered_vtbl = {
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- close_istream_filtered,
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- read_istream_filtered,
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-};
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-
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static struct git_istream *attach_stream_filter(struct git_istream *st,
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struct stream_filter *filter)
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{
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struct git_istream *ifs = xmalloc(sizeof(*ifs));
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struct filtered_istream *fs = &(ifs->u.filtered);
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- ifs->vtbl = &filtered_vtbl;
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+ ifs->close = close_istream_filtered;
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+ ifs->read = read_istream_filtered;
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fs->upstream = st;
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fs->filter = filter;
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fs->i_end = fs->i_ptr = 0;
@@ -225,11 +219,6 @@ static int close_istream_loose(struct git_istream *st)
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return 0;
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}
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-static struct stream_vtbl loose_vtbl = {
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- close_istream_loose,
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- read_istream_loose,
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-};
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-
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static int open_istream_loose(struct git_istream *st, struct repository *r,
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const struct object_id *oid,
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enum object_type *type)
@@ -251,8 +240,9 @@ static int open_istream_loose(struct git_istream *st, struct repository *r,
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st->u.loose.hdr_used = strlen(st->u.loose.hdr) + 1;
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st->u.loose.hdr_avail = st->z.total_out;
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st->z_state = z_used;
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+ st->close = close_istream_loose;
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+ st->read = read_istream_loose;
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- st->vtbl = &loose_vtbl;
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return 0;
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}
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@@ -328,11 +318,6 @@ static int close_istream_pack_non_delta(struct git_istream *st)
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return 0;
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}
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-static struct stream_vtbl pack_non_delta_vtbl = {
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- close_istream_pack_non_delta,
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- read_istream_pack_non_delta,
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-};
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-
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static int open_istream_pack_non_delta(struct git_istream *st,
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struct repository *r,
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const struct object_id *oid,
@@ -358,7 +343,9 @@ static int open_istream_pack_non_delta(struct git_istream *st,
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break;
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}
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st->z_state = z_unused;
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- st->vtbl = &pack_non_delta_vtbl;
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+ st->close = close_istream_pack_non_delta;
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+ st->read = read_istream_pack_non_delta;
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+
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return 0;
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}
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@@ -389,17 +376,13 @@ static ssize_t read_istream_incore(struct git_istream *st, char *buf, size_t sz)
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return read_size;
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}
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-static struct stream_vtbl incore_vtbl = {
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- close_istream_incore,
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- read_istream_incore,
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-};
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-
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static int open_istream_incore(struct git_istream *st, struct repository *r,
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const struct object_id *oid, enum object_type *type)
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{
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st->u.incore.buf = read_object_file_extended(r, oid, type, &st->size, 0);
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st->u.incore.read_ptr = 0;
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- st->vtbl = &incore_vtbl;
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+ st->close = close_istream_incore;
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+ st->read = read_istream_incore;
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return st->u.incore.buf ? 0 : -1;
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}
@@ -408,10 +391,10 @@ static int open_istream_incore(struct git_istream *st, struct repository *r,
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* static helpers variables and functions for users of streaming interface
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*****************************************************************************/
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-static open_istream_fn istream_source(struct git_istream *st,
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- struct repository *r,
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- const struct object_id *oid,
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- enum object_type *type)
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+static int istream_source(struct git_istream *st,
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+ struct repository *r,
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+ const struct object_id *oid,
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+ enum object_type *type)
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{
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unsigned long size;
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int status;
@@ -421,20 +404,23 @@ static open_istream_fn istream_source(struct git_istream *st,
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oi.sizep = &size;
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status = oid_object_info_extended(r, oid, &oi, 0);
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if (status < 0)
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- return NULL;
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+ return status;
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switch (oi.whence) {
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case OI_LOOSE:
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- return open_istream_loose;
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+ st->open = open_istream_loose;
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+ return 0;
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case OI_PACKED:
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if (!oi.u.packed.is_delta && big_file_threshold < size) {
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st->u.in_pack.pack = oi.u.packed.pack;
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st->u.in_pack.pos = oi.u.packed.offset;
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- return open_istream_pack_non_delta;
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+ st->open = open_istream_pack_non_delta;
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+ return 0;
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}
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/* fallthru */
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default:
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- return open_istream_incore;
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+ st->open = open_istream_incore;
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+ return 0;
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}
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}
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@@ -444,14 +430,14 @@ static open_istream_fn istream_source(struct git_istream *st,
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int close_istream(struct git_istream *st)
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{
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- int r = st->vtbl->close(st);
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+ int r = st->close(st);
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free(st);
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return r;
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}
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ssize_t read_istream(struct git_istream *st, void *buf, size_t sz)
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{
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- return st->vtbl->read(st, buf, sz);
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+ return st->read(st, buf, sz);
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}
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struct git_istream *open_istream(struct repository *r,
@@ -462,14 +448,14 @@ struct git_istream *open_istream(struct repository *r,
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{
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struct git_istream *st = xmalloc(sizeof(*st));
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const struct object_id *real = lookup_replace_object(r, oid);
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- open_istream_fn open_fn = istream_source(st, r, real, type);
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+ int ret = istream_source(st, r, real, type);
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- if (!open_fn) {
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+ if (ret) {
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free(st);
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return NULL;
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}
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- if (open_fn(st, r, real, type)) {
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+ if (st->open(st, r, real, type)) {
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if (open_istream_incore(st, r, real, type)) {
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free(st);
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return NULL;