git/repack-promisor.c

103 lines
2.9 KiB
C

#include "git-compat-util.h"
#include "repack.h"
#include "run-command.h"
#include "hex.h"
#include "repository.h"
#include "packfile.h"
#include "path.h"
#include "pack.h"
struct write_oid_context {
struct child_process *cmd;
const struct git_hash_algo *algop;
};
/*
* Write oid to the given struct child_process's stdin, starting it first if
* necessary.
*/
static int write_oid(const struct object_id *oid,
struct packed_git *pack UNUSED,
uint32_t pos UNUSED, void *data)
{
struct write_oid_context *ctx = data;
struct child_process *cmd = ctx->cmd;
if (cmd->in == -1) {
if (start_command(cmd))
die(_("could not start pack-objects to repack promisor objects"));
}
if (write_in_full(cmd->in, oid_to_hex(oid), ctx->algop->hexsz) < 0 ||
write_in_full(cmd->in, "\n", 1) < 0)
die(_("failed to feed promisor objects to pack-objects"));
return 0;
}
void repack_promisor_objects(struct repository *repo,
const struct pack_objects_args *args,
struct string_list *names, const char *packtmp)
{
struct write_oid_context ctx;
struct child_process cmd = CHILD_PROCESS_INIT;
FILE *out;
struct strbuf line = STRBUF_INIT;
prepare_pack_objects(&cmd, args, packtmp);
cmd.in = -1;
/*
* NEEDSWORK: Giving pack-objects only the OIDs without any ordering
* hints may result in suboptimal deltas in the resulting pack. See if
* the OIDs can be sent with fake paths such that pack-objects can use a
* {type -> existing pack order} ordering when computing deltas instead
* of a {type -> size} ordering, which may produce better deltas.
*/
ctx.cmd = &cmd;
ctx.algop = repo->hash_algo;
for_each_packed_object(repo, write_oid, &ctx,
FOR_EACH_OBJECT_PROMISOR_ONLY);
if (cmd.in == -1) {
/* No packed objects; cmd was never started */
child_process_clear(&cmd);
return;
}
close(cmd.in);
out = xfdopen(cmd.out, "r");
while (strbuf_getline_lf(&line, out) != EOF) {
struct string_list_item *item;
char *promisor_name;
if (line.len != repo->hash_algo->hexsz)
die(_("repack: Expecting full hex object ID lines only from pack-objects."));
item = string_list_append(names, line.buf);
/*
* pack-objects creates the .pack and .idx files, but not the
* .promisor file. Create the .promisor file, which is empty.
*
* NEEDSWORK: fetch-pack sometimes generates non-empty
* .promisor files containing the ref names and associated
* hashes at the point of generation of the corresponding
* packfile, but this would not preserve their contents. Maybe
* concatenate the contents of all .promisor files instead of
* just creating a new empty file.
*/
promisor_name = mkpathdup("%s-%s.promisor", packtmp,
line.buf);
write_promisor_file(promisor_name, NULL, 0);
item->util = generated_pack_populate(item->string, packtmp);
free(promisor_name);
}
fclose(out);
if (finish_command(&cmd))
die(_("could not finish pack-objects to repack promisor objects"));
strbuf_release(&line);
}