This adds the infrastructure to launch and use long running
sub-processes as external odb helpers.
For now only the 'init' and 'get_direct' capabilities are
supported with sub-processes.
Signed-off-by: Christian Couder <chriscool@xxxxxxxxxxxxx>
---
external-odb.c | 46 +++---
odb-helper.c | 474 ++++++++++++++++++++++++++++++++++++++++++++++++++++++---
sha1_file.c | 12 +-
3 files changed, 491 insertions(+), 41 deletions(-)
diff --git a/external-odb.c b/external-odb.c
index f38c2c2fe3..50c1cec50b 100644
--- a/external-odb.c
+++ b/external-odb.c
@@ -81,29 +81,11 @@ const char *external_odb_root(void)
return root;
}
-int external_odb_has_object(const unsigned char *sha1)
-{
- struct odb_helper *o;
-
- external_odb_init();
-
- for (o = helpers; o; o = o->next) {
- if (!(o->supported_capabilities & ODB_HELPER_CAP_HAVE))
- return 1;
- if (odb_helper_has_object(o, sha1))
- return 1;
- }
- return 0;
-}
-
-int external_odb_get_object(const unsigned char *sha1)
+static int external_odb_do_get_object(const unsigned char *sha1)
{
struct odb_helper *o;
const char *path;
- if (!external_odb_has_object(sha1))
- return -1;
-
path = sha1_file_name_alt(external_odb_root(), sha1);
safe_create_leading_directories_const(path);
prepare_external_alt_odb();
@@ -157,6 +139,32 @@ int external_odb_get_direct(const unsigned char *sha1)
return -1;
}
+int external_odb_has_object(const unsigned char *sha1)
+{
+ struct odb_helper *o;
+
+ external_odb_init();
+
+ for (o = helpers; o; o = o->next) {
+ if (!(o->supported_capabilities & ODB_HELPER_CAP_HAVE)) {
+ if (o->supported_capabilities & ODB_HELPER_CAP_GET_DIRECT)
+ return 1;
+ return !external_odb_do_get_object(sha1);
+ }
+ if (odb_helper_has_object(o, sha1))
+ return 1;
+ }
+ return 0;
+}
+
+int external_odb_get_object(const unsigned char *sha1)
+{
+ if (!external_odb_has_object(sha1))
+ return -1;
+
+ return external_odb_do_get_object(sha1);
+}
+
int external_odb_put_object(const void *buf, size_t len,
const char *type, unsigned char *sha1)
{
diff --git a/odb-helper.c b/odb-helper.c
index 91b4de1a05..a67dfddca0 100644
--- a/odb-helper.c
+++ b/odb-helper.c
@@ -5,6 +5,22 @@
#include "run-command.h"
#include "sha1-lookup.h"
#include "fetch-object.h"
+#include "sub-process.h"
+#include "pkt-line.h"
+#include "sigchain.h"
+
+struct object_process {
+ struct subprocess_entry subprocess;
+ unsigned int supported_capabilities;
+};
+
+static struct hashmap subprocess_map;
+
+static int check_object_process_status(int fd, struct strbuf *status)
+{
+ subprocess_read_status(fd, status);
+ return strcmp(status->buf, "success");
+}
static void parse_capabilities(char *cap_buf,
unsigned int *supported_capabilities,
@@ -40,6 +56,384 @@ static void parse_capabilities(char *cap_buf,
string_list_clear(&cap_list, 0);
}
+static int start_object_process_fn(struct subprocess_entry *subprocess)
+{
+ static int versions[] = {1, 0};
+ static struct subprocess_capability capabilities[] = {
+ { "get_git_obj", ODB_HELPER_CAP_GET_GIT_OBJ },
+ { "get_raw_obj", ODB_HELPER_CAP_GET_RAW_OBJ },
+ { "get_direct", ODB_HELPER_CAP_GET_DIRECT },
+ { "put_git_obj", ODB_HELPER_CAP_PUT_GIT_OBJ },
+ { "put_raw_obj", ODB_HELPER_CAP_PUT_RAW_OBJ },
+ { "put_direct", ODB_HELPER_CAP_PUT_DIRECT },
+ { "have", ODB_HELPER_CAP_HAVE },
+ { NULL, 0 }
+ };
+ struct object_process *entry = (struct object_process *)subprocess;
+ return subprocess_handshake(subprocess, "git-read-object", versions, NULL,
+ capabilities,
+ &entry->supported_capabilities);
+}
+
+static struct object_process *launch_object_process(struct odb_helper *o,
+ unsigned int capability)
+{
+ struct object_process *entry = NULL;
+
+ if (!subprocess_map.tablesize)
+ hashmap_init(&subprocess_map, (hashmap_cmp_fn) cmd2process_cmp, NULL, 0);
+ else
+ entry = (struct object_process *)subprocess_find_entry(&subprocess_map, o->dealer);
+
+ fflush(NULL);
+
+ if (!entry) {
+ entry = xmalloc(sizeof(*entry));
+ entry->supported_capabilities = 0;
+
+ if (subprocess_start(&subprocess_map, &entry->subprocess, o->dealer, start_object_process_fn)) {
+ error("Could not launch process for cmd '%s'", o->dealer);
+ free(entry);
+ return NULL;
+ }
+ }
+
+ o->supported_capabilities = entry->supported_capabilities;
+
+ if (capability && !(capability & entry->supported_capabilities)) {
+ error("The cmd '%s' does not support capability '%d'", o->dealer, capability);
+ return NULL;
+ }
+
+ sigchain_push(SIGPIPE, SIG_IGN);
+
+ return entry;
+}
+
+static int check_object_process_error(int err,
+ const char *status,
+ struct object_process *entry,
+ const char *cmd,
+ unsigned int capability)
+{
+ sigchain_pop(SIGPIPE);
+
+ if (!err)
+ return 0;
+
+ if (!strcmp(status, "error")) {
+ /* The process signaled a problem with the file. */
+ } else if (!strcmp(status, "notfound")) {
+ /* Object was not found */
+ err = -1;
+ } else if (!strcmp(status, "abort")) {
+ /*
+ * The process signaled a permanent problem. Don't try to read
+ * objects with the same command for the lifetime of the current
+ * Git process.
+ */
+ if (capability)
+ entry->supported_capabilities &= ~capability;
+ } else {
+ /*
+ * Something went wrong with the read-object process.
+ * Force shutdown and restart if needed.
+ */
+ error("external object process '%s' failed", cmd);
+ subprocess_stop(&subprocess_map, &entry->subprocess);
+ free(entry);
+ }
+
+ return err;
+}
+
+static int send_init_packets(struct object_process *entry,
+ struct strbuf *status)
+{
+ struct child_process *process = &entry->subprocess.process;
+
+ return packet_write_fmt_gently(process->in, "command=init\n") ||
+ packet_flush_gently(process->in) ||
+ check_object_process_status(process->out, status);
+}
+
+static int init_object_process(struct odb_helper *o)
+{
+ int err;
+ struct strbuf status = STRBUF_INIT;
+ struct object_process *entry = launch_object_process(o, 0);
+ if (!entry)
+ return -1;
+
+ err = send_init_packets(entry, &status);
+
+ return check_object_process_error(err, status.buf, entry,
+ o->dealer, 0);
+}
+
+static ssize_t read_packetized_raw_object_to_fd(struct odb_helper *o,
+ const unsigned char *sha1,
+ int fd_in, int fd_out)
+{
+ ssize_t total_read = 0;
+ unsigned long total_got = 0;
+ int packet_len;
+
+ char hdr[32];
+ int hdrlen;
+
+ int ret = Z_STREAM_END;
+ unsigned char compressed[4096];
+ git_zstream stream;
+ git_SHA_CTX hash;
+ unsigned char real_sha1[20];
+
+ off_t size;
+ enum object_type type;
+ const char *s;
+ int pkt_size;
+ char *size_buf;
+
+ size_buf = packet_read_line(fd_in, &pkt_size);
+ if (!skip_prefix(size_buf, "size=", &s))
+ return error("odb helper '%s' did not send size of plain object", o->name);
+ size = strtoumax(s, NULL, 10);
+ if (!skip_prefix(packet_read_line(fd_in, NULL), "kind=", &s))
+ return error("odb helper '%s' did not send kind of plain object", o->name);
+ /* Check if the object is not available */
+ if (!strcmp(s, "none"))
+ return -1;
+ type = type_from_string_gently(s, strlen(s), 1);
+ if (type < 0)
+ return error("odb helper '%s' sent bad type '%s'", o->name, s);
+
+ /* Set it up */
+ git_deflate_init(&stream, zlib_compression_level);
+ stream.next_out = compressed;
+ stream.avail_out = sizeof(compressed);
+ git_SHA1_Init(&hash);
+
+ /* First header.. */
+ hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), size) + 1;
+ stream.next_in = (unsigned char *)hdr;
+ stream.avail_in = hdrlen;
+ while (git_deflate(&stream, 0) == Z_OK)
+ ; /* nothing */
+ git_SHA1_Update(&hash, hdr, hdrlen);
+
+ for (;;) {
+ /* packet_read() writes a '\0' extra byte at the end */
+ char buf[LARGE_PACKET_DATA_MAX + 1];
+
+ packet_len = packet_read(fd_in, NULL, NULL,
+ buf, LARGE_PACKET_DATA_MAX + 1,
+ PACKET_READ_GENTLE_ON_EOF);
+
+ if (packet_len <= 0)
+ break;
+
+ total_got += packet_len;
+
+ /* Then the data itself.. */
+ stream.next_in = (void *)buf;
+ stream.avail_in = packet_len;
+ do {
+ unsigned char *in0 = stream.next_in;
+ ret = git_deflate(&stream, Z_FINISH);
+ git_SHA1_Update(&hash, in0, stream.next_in - in0);
+ write_or_die(fd_out, compressed, stream.next_out - compressed);
+ stream.next_out = compressed;
+ stream.avail_out = sizeof(compressed);
+ } while (ret == Z_OK);
+
+ total_read += packet_len;
+ }
+
+ if (packet_len < 0) {
+ error("unable to read from odb helper '%s': %s",
+ o->name, strerror(errno));
+ git_deflate_end(&stream);
+ return packet_len;
+ }
+
+ if (ret != Z_STREAM_END) {
+ warning("bad zlib data from odb helper '%s' for %s",
+ o->name, sha1_to_hex(sha1));
+ return -1;
+ }
+
+ ret = git_deflate_end_gently(&stream);
+ if (ret != Z_OK) {
+ warning("deflateEnd on object %s from odb helper '%s' failed (%d)",
+ sha1_to_hex(sha1), o->name, ret);
+ return -1;
+ }
+ git_SHA1_Final(real_sha1, &hash);
+ if (hashcmp(sha1, real_sha1)) {
+ warning("sha1 mismatch from odb helper '%s' for %s (got %s)",
+ o->name, sha1_to_hex(sha1), sha1_to_hex(real_sha1));
+ return -1;
+ }
+ if (total_got != size) {
+ warning("size mismatch from odb helper '%s' for %s (%lu != %lu)",
+ o->name, sha1_to_hex(sha1), total_got, size);
+ return -1;
+ }
+
+ return total_read;
+}
+
+static ssize_t read_packetized_git_object_to_fd(struct odb_helper *o,
+ const unsigned char *sha1,
+ int fd_in, int fd_out)
+{
+ ssize_t total_read = 0;
+ unsigned long total_got = 0;
+ int packet_len;
+ git_zstream stream;
+ int zret = Z_STREAM_END;
+ git_SHA_CTX hash;
+ unsigned char real_sha1[20];
+ struct strbuf header = STRBUF_INIT;
+ unsigned long hdr_size;
+
+ memset(&stream, 0, sizeof(stream));
+ git_inflate_init(&stream);
+ git_SHA1_Init(&hash);
+
+ for (;;) {
+ /* packet_read() writes a '\0' extra byte at the end */
+ char buf[LARGE_PACKET_DATA_MAX + 1];
+
+ packet_len = packet_read(fd_in, NULL, NULL,
+ buf, LARGE_PACKET_DATA_MAX + 1,
+ PACKET_READ_GENTLE_ON_EOF);
+
+ if (packet_len <= 0)
+ break;
+
+ write_or_die(fd_out, buf, packet_len);
+
+ stream.next_in = (unsigned char *)buf;
+ stream.avail_in = packet_len;
+ do {
+ unsigned char inflated[4096];
+ unsigned long got;
+
+ stream.next_out = inflated;
+ stream.avail_out = sizeof(inflated);
+ zret = git_inflate(&stream, Z_SYNC_FLUSH);
+ got = sizeof(inflated) - stream.avail_out;
+
+ git_SHA1_Update(&hash, inflated, got);
+ /* skip header when counting size */
+ if (!total_got) {
+ const unsigned char *p = memchr(inflated, '\0', got);
+ if (p) {
+ unsigned long hdr_last = p - inflated + 1;
+ strbuf_add(&header, inflated, hdr_last);
+ got -= hdr_last;
+ } else {
+ strbuf_add(&header, inflated, got);
+ got = 0;
+ }
+ }
+ total_got += got;
+ } while (stream.avail_in && zret == Z_OK);
+
+ total_read += packet_len;
+ }
+
+ git_inflate_end(&stream);
+
+ if (packet_len < 0)
+ return packet_len;
+
+ git_SHA1_Final(real_sha1, &hash);
+
+ if (zret != Z_STREAM_END) {
+ warning("bad zlib data from odb helper '%s' for %s",
+ o->name, sha1_to_hex(sha1));
+ return -1;
+ }
+ if (hashcmp(real_sha1, sha1)) {
+ warning("sha1 mismatch from odb helper '%s' for %s (got %s)",
+ o->name, sha1_to_hex(sha1), sha1_to_hex(real_sha1));
+ return -1;
+ }
+ if (parse_sha1_header(header.buf, &hdr_size) < 0) {
+ warning("could not parse header from odb helper '%s' for %s",
+ o->name, sha1_to_hex(sha1));
+ return -1;
+ }
+ if (total_got != hdr_size) {
+ warning("size mismatch from odb helper '%s' for %s (%lu != %lu)",
+ o->name, sha1_to_hex(sha1), total_got, hdr_size);
+ return -1;
+ }
+
+ return total_read;
+}
+
+static int send_get_packets(struct odb_helper *o,
+ struct object_process *entry,
+ const unsigned char *sha1,
+ int fd,
+ unsigned int *cur_cap,
+ struct strbuf *status)
+{
+ const char *instruction;
+ int err;
+ struct child_process *process = &entry->subprocess.process;
+
+ if (entry->supported_capabilities & ODB_HELPER_CAP_GET_GIT_OBJ) {
+ *cur_cap = ODB_HELPER_CAP_GET_GIT_OBJ;
+ instruction = "get_git_obj";
+ } else if (entry->supported_capabilities & ODB_HELPER_CAP_GET_RAW_OBJ) {
+ *cur_cap = ODB_HELPER_CAP_GET_RAW_OBJ;
+ instruction = "get_raw_obj";
+ } else if (entry->supported_capabilities & ODB_HELPER_CAP_GET_DIRECT) {
+ *cur_cap = ODB_HELPER_CAP_GET_DIRECT;
+ instruction = "get_direct";
+ } else {
+ BUG("No known ODB_HELPER_CAP_GET_XXX capability!");
+ }
+
+ err = packet_write_fmt_gently(process->in, "command=%s\n", instruction);
+ if (err)
+ return err;
+
+ err = packet_write_fmt_gently(process->in, "sha1=%s\n", sha1_to_hex(sha1));
+ if (err)
+ return err;
+
+ err = packet_flush_gently(process->in);
+ if (err)
+ return err;
+
+ if (entry->supported_capabilities & ODB_HELPER_CAP_GET_RAW_OBJ)
+ err = read_packetized_raw_object_to_fd(o, sha1, process->out, fd) < 0;
+ else if (entry->supported_capabilities & ODB_HELPER_CAP_GET_GIT_OBJ)
+ err = read_packetized_git_object_to_fd(o, sha1, process->out, fd) < 0;
+
+ return check_object_process_status(process->out, status);
+}
+
+static int get_object_process(struct odb_helper *o, const unsigned char *sha1, int fd)
+{
+ int err;
+ struct strbuf status = STRBUF_INIT;
+ unsigned int cur_cap = 0;
+ struct object_process *entry = launch_object_process(o, 0);
+ if (!entry)
+ return -1;
+
+ err = send_get_packets(o, entry, sha1, fd, &cur_cap, &status);
+
+ return check_object_process_error(err, status.buf, entry,
+ o->dealer, cur_cap);
+}
+
struct odb_helper *odb_helper_new(const char *name, int namelen)
{
struct odb_helper *o;
@@ -118,15 +512,12 @@ static int odb_helper_finish(struct odb_helper *o,
return 0;
}
-int odb_helper_init(struct odb_helper *o)
+static int init_object_script(struct odb_helper *o)
{
struct odb_helper_cmd cmd;
FILE *fh;
struct strbuf line = STRBUF_INIT;
- if (o->type != ODB_HELPER_SCRIPT_CMD)
- return 0;
-
if (odb_helper_start(o, &cmd, 0, "init") < 0)
return -1;
@@ -141,6 +532,21 @@ int odb_helper_init(struct odb_helper *o)
return 0;
}
+int odb_helper_init(struct odb_helper *o)
+{
+ int res = 0;
+ uint64_t start = getnanotime();
+
+ if (o->type == ODB_HELPER_SCRIPT_CMD)
+ res = init_object_script(o);
+ else if (o->type == ODB_HELPER_SUBPROCESS_CMD)
+ res = init_object_process(o);
+
+ trace_performance_since(start, "odb_helper_init");
+
+ return res;
+}
+
static int parse_object_line(struct odb_helper_object *o, const char *line)
{
char *end;
@@ -435,36 +841,45 @@ static int odb_helper_get_git_object(struct odb_helper *o,
return 0;
}
+static int get_direct_script(struct odb_helper *o, const unsigned char *sha1)
+{
+ struct odb_helper_cmd cmd;
+
+ if (odb_helper_start(o, &cmd, 0, "get_direct %s", sha1_to_hex(sha1)) < 0)
+ return -1;
+ if (odb_helper_finish(o, &cmd))
+ return -1;
+ return 0;
+}
+
int odb_helper_get_direct(struct odb_helper *o,
const unsigned char *sha1)
{
- uint64_t start = getnanotime();
-
- if (o->type == ODB_HELPER_GIT_REMOTE) {
- fetch_object(o->dealer, sha1);
- } else {
- struct odb_helper_object *obj;
- struct odb_helper_cmd cmd;
+ int res = 0;
+ uint64_t start;
- obj = odb_helper_lookup(o, sha1);
+ if (o->supported_capabilities & ODB_HELPER_CAP_HAVE &&
+ o->type != ODB_HELPER_GIT_REMOTE) {
+ struct odb_helper_object *obj = odb_helper_lookup(o, sha1);
if (!obj)
return -1;
+ }
- if (odb_helper_start(o, &cmd, 0, "get_direct %s", sha1_to_hex(sha1)) < 0)
- return -1;
+ start = getnanotime();
- if (odb_helper_finish(o, &cmd))
- return -1;
- }
+ if (o->type == ODB_HELPER_GIT_REMOTE)
+ fetch_object(o->dealer, sha1);
+ else if (o->type == ODB_HELPER_SCRIPT_CMD)
+ res = get_direct_script(o, sha1);
+ else
+ res = get_object_process(o, sha1, -1);
trace_performance_since(start, "odb_helper_get_direct");
- return 0;
+ return res;
}
-int odb_helper_get_object(struct odb_helper *o,
- const unsigned char *sha1,
- int fd)
+static int get_object_script(struct odb_helper *o, const unsigned char *sha1, int fd)
{
if (o->supported_capabilities & ODB_HELPER_CAP_GET_GIT_OBJ)
return odb_helper_get_git_object(o, sha1, fd);
@@ -476,6 +891,23 @@ int odb_helper_get_object(struct odb_helper *o,
BUG("invalid get capability (capabilities: '%d')", o->supported_capabilities);
}
+int odb_helper_get_object(struct odb_helper *o,
+ const unsigned char *sha1,
+ int fd)
+{
+ int res = 0;
+ uint64_t start = getnanotime();
+
+ if (o->type == ODB_HELPER_SCRIPT_CMD)
+ res = get_object_script(o, sha1, fd);
+ else if (o->type == ODB_HELPER_SUBPROCESS_CMD)
+ res = get_object_process(o, sha1, fd);
+
+ trace_performance_since(start, "odb_helper_get_object");
+
+ return res;
+}
+
int odb_helper_put_object(struct odb_helper *o,
const void *buf, size_t len,
const char *type, unsigned char *sha1)
diff --git a/sha1_file.c b/sha1_file.c
index 8c873554b2..300029459f 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -735,7 +735,17 @@ int check_and_freshen_file(const char *fn, int freshen)
static int check_and_freshen_local(const unsigned char *sha1, int freshen)
{
- return check_and_freshen_file(sha1_file_name(sha1), freshen);
+ int ret;
+ int tried_hook = 0;
+
+retry:
+ ret = check_and_freshen_file(sha1_file_name(sha1), freshen);
+ if (!ret && !tried_hook) {
+ tried_hook = 1;
+ if (!external_odb_get_direct(sha1))
+ goto retry;
+ }
+ return ret;
}
static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
--
2.16.0.rc0.16.g82191dbc6c.dirty
