[PATCH] Support alternates and http-alternates in http-fetch
From: Daniel Barkalow <hidden>
Date: 2016-06-15 22:42:06
Subsystem:
the rest · Maintainer:
Linus Torvalds
This allows the remote repository to refer to additional repositories in a file objects/info/http-alternates or objects/info/alternates. Each line may be: a relative path, starting with ../, to get from the objects directory of the starting repository to the objects directory of the added repository. an absolute path of the objects directory of the added repository (on the same server). (only in http-alternates) a full URL of the objects directory of the added repository. Signed-off-by: Daniel Barkalow <redacted> --- http-fetch.c | 202 ++++++++++++++++++++++++++++++++++++++++++++++++---------- 1 files changed, 166 insertions(+), 36 deletions(-) 7640b93541f9422e8d101959c2f6c4fc3277e4f8
diff --git a/http-fetch.c b/http-fetch.c
--- a/http-fetch.c
+++ b/http-fetch.c@@ -16,7 +16,17 @@ static CURL *curl; static struct curl_slist *no_pragma_header; -static char *base; +static char *initial_base; + +struct alt_base +{ + char *base; + int got_indices; + struct packed_git *packs; + struct alt_base *next; +}; + +struct alt_base *alt = NULL; static SHA_CTX c; static z_stream stream;
@@ -72,11 +82,9 @@ void prefetch(unsigned char *sha1) { } -static int got_indices = 0; - -static struct packed_git *packs = NULL; +static int got_alternates = 0; -static int fetch_index(unsigned char *sha1) +static int fetch_index(struct alt_base *repo, unsigned char *sha1) { char *filename; char *url;
@@ -90,9 +98,9 @@ static int fetch_index(unsigned char *sh fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1)); - url = xmalloc(strlen(base) + 64); + url = xmalloc(strlen(repo->base) + 64); sprintf(url, "%s/objects/pack/pack-%s.idx", - base, sha1_to_hex(sha1)); + repo->base, sha1_to_hex(sha1)); filename = sha1_pack_index_name(sha1); indexfile = fopen(filename, "w");
@@ -114,22 +122,123 @@ static int fetch_index(unsigned char *sh return 0; } -static int setup_index(unsigned char *sha1) +static int setup_index(struct alt_base *repo, unsigned char *sha1) { struct packed_git *new_pack; if (has_pack_file(sha1)) return 0; // don't list this as something we can get - if (fetch_index(sha1)) + if (fetch_index(repo, sha1)) return -1; new_pack = parse_pack_index(sha1); - new_pack->next = packs; - packs = new_pack; + new_pack->next = repo->packs; + repo->packs = new_pack; return 0; } -static int fetch_indices(void) +static int fetch_alternates(char *base) +{ + int ret = 0; + struct buffer buffer; + char *url; + char *data; + int i = 0; + int http_specific = 1; + if (got_alternates) + return 0; + data = xmalloc(4096); + buffer.size = 4095; + buffer.posn = 0; + buffer.buffer = data; + + if (get_verbosely) + fprintf(stderr, "Getting alternates list\n"); + + url = xmalloc(strlen(base) + 31); + sprintf(url, "%s/objects/info/http-alternates", base); + + curl_easy_setopt(curl, CURLOPT_FILE, &buffer); + curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer); + curl_easy_setopt(curl, CURLOPT_URL, url); + + if (curl_easy_perform(curl) || !buffer.posn) { + http_specific = 0; + + sprintf(url, "%s/objects/info/alternates", base); + + curl_easy_setopt(curl, CURLOPT_FILE, &buffer); + curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer); + curl_easy_setopt(curl, CURLOPT_URL, url); + + if (curl_easy_perform(curl)) { + return 0; + } + } + + data[buffer.posn] = '\0'; + + while (i < buffer.posn) { + int posn = i; + while (posn < buffer.posn && data[posn] != '\n') + posn++; + if (data[posn] == '\n') { + int okay = 0; + int serverlen = 0; + struct alt_base *newalt; + char *target = NULL; + if (data[i] == '/') { + serverlen = strchr(base + 8, '/') - base; + okay = 1; + } else if (!memcmp(data + i, "../", 3)) { + i += 3; + serverlen = strlen(base); + while (i + 2 < posn && + !memcmp(data + i, "../", 3)) { + do { + serverlen--; + } while (serverlen && + base[serverlen - 1] != '/'); + i += 3; + } + // If the server got removed, give up. + okay = strchr(base, ':') - base + 3 < + serverlen; + } else if (http_specific) { + char *colon = strchr(data + i, ':'); + char *slash = strchr(data + i, '/'); + if (colon && slash && colon < data + posn && + slash < data + posn && colon < slash) { + okay = 1; + } + } + // skip 'objects' at end + if (okay) { + target = xmalloc(serverlen + posn - i - 6); + strncpy(target, base, serverlen); + strncpy(target + serverlen, data + i, + posn - i - 7); + target[serverlen + posn - i - 7] = '\0'; + if (get_verbosely) + fprintf(stderr, + "Also look at %s\n", target); + newalt = xmalloc(sizeof(*newalt)); + newalt->next = alt; + newalt->base = target; + newalt->got_indices = 0; + newalt->packs = NULL; + alt = newalt; + ret++; + } + } + i = posn + 1; + } + got_alternates = 1; + + return ret; +} + +static int fetch_indices(struct alt_base *repo) { unsigned char sha1[20]; char *url;
@@ -137,7 +246,7 @@ static int fetch_indices(void) char *data; int i = 0; - if (got_indices) + if (repo->got_indices) return 0; data = xmalloc(4096);
@@ -148,8 +257,8 @@ static int fetch_indices(void) if (get_verbosely) fprintf(stderr, "Getting pack list\n"); - url = xmalloc(strlen(base) + 21); - sprintf(url, "%s/objects/info/packs", base); + url = xmalloc(strlen(repo->base) + 21); + sprintf(url, "%s/objects/info/packs", repo->base); curl_easy_setopt(curl, CURLOPT_FILE, &buffer); curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
@@ -157,10 +266,10 @@ static int fetch_indices(void) curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL); if (curl_easy_perform(curl)) { - return error("Unable to get pack index %s", url); + return -1; } - do { + while (i < buffer.posn) { switch (data[i]) { case 'P': i++;
@@ -168,7 +277,7 @@ static int fetch_indices(void) !strncmp(data + i, " pack-", 6) && !strncmp(data + i + 46, ".pack\n", 6)) { get_sha1_hex(data + i + 6, sha1); - setup_index(sha1); + setup_index(repo, sha1); i += 51; break; }
@@ -177,13 +286,13 @@ static int fetch_indices(void) i++; } i++; - } while (i < buffer.posn); + } - got_indices = 1; + repo->got_indices = 1; return 0; } -static int fetch_pack(unsigned char *sha1) +static int fetch_pack(struct alt_base *repo, unsigned char *sha1) { char *url; struct packed_git *target;
@@ -191,12 +300,11 @@ static int fetch_pack(unsigned char *sha FILE *packfile; char *filename; - if (fetch_indices()) + if (fetch_indices(repo)) return -1; - target = find_sha1_pack(sha1, packs); + target = find_sha1_pack(sha1, repo->packs); if (!target) - return error("Couldn't get %s: not separate or in any pack", - sha1_to_hex(sha1)); + return -1; if (get_verbosely) { fprintf(stderr, "Getting pack %s\n",
@@ -205,9 +313,9 @@ static int fetch_pack(unsigned char *sha sha1_to_hex(sha1)); } - url = xmalloc(strlen(base) + 65); + url = xmalloc(strlen(repo->base) + 65); sprintf(url, "%s/objects/pack/pack-%s.pack", - base, sha1_to_hex(target->sha1)); + repo->base, sha1_to_hex(target->sha1)); filename = sha1_pack_name(target->sha1); packfile = fopen(filename, "w");
@@ -227,7 +335,7 @@ static int fetch_pack(unsigned char *sha fclose(packfile); - lst = &packs; + lst = &repo->packs; while (*lst != target) lst = &((*lst)->next); *lst = (*lst)->next;
@@ -237,7 +345,7 @@ static int fetch_pack(unsigned char *sha return 0; } -int fetch(unsigned char *sha1) +int fetch_object(struct alt_base *repo, unsigned char *sha1) { char *hex = sha1_to_hex(sha1); char *filename = sha1_file_name(sha1);
@@ -261,9 +369,9 @@ int fetch(unsigned char *sha1) curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file); curl_easy_setopt(curl, CURLOPT_HTTPHEADER, no_pragma_header); - url = xmalloc(strlen(base) + 50); - strcpy(url, base); - posn = url + strlen(base); + url = xmalloc(strlen(repo->base) + 50); + strcpy(url, repo->base); + posn = url + strlen(repo->base); strcpy(posn, "objects/"); posn += 8; memcpy(posn, hex, 2);
@@ -275,9 +383,7 @@ int fetch(unsigned char *sha1) if (curl_easy_perform(curl)) { unlink(filename); - if (fetch_pack(sha1)) - return error("Tried %s", url); - return 0; + return -1; } close(local);
@@ -296,11 +402,30 @@ int fetch(unsigned char *sha1) return 0; } +int fetch(unsigned char *sha1) +{ + struct alt_base *altbase = alt; + while (altbase) { + if (!fetch_object(altbase, sha1)) + return 0; + if (!fetch_pack(altbase, sha1)) + return 0; + if (fetch_alternates(altbase->base) > 0) { + altbase = alt; + continue; + } + altbase = altbase->next; + } + return error("Unable to find %s under %s\n", sha1_to_hex(sha1), + initial_base); +} + int fetch_ref(char *ref, unsigned char *sha1) { char *url, *posn; char hex[42]; struct buffer buffer; + char *base = initial_base; buffer.size = 41; buffer.posn = 0; buffer.buffer = hex;
@@ -368,7 +493,12 @@ int main(int argc, char **argv) curl_easy_setopt(curl, CURLOPT_NETRC, CURL_NETRC_OPTIONAL); #endif - base = url; + alt = xmalloc(sizeof(*alt)); + alt->base = url; + alt->got_indices = 0; + alt->packs = NULL; + alt->next = NULL; + initial_base = url; if (pull(commit_id)) return 1;