Merge remote branch 'remotes/trast-doc/for-next'
[gitweb.git] / http.c
diff --git a/http.c b/http.c
index b5323a68b74fe16bfed55d1bf002b39296db0a60..deab59551dad9a0d2c2e86d75071fa561e4cbf1a 100644 (file)
--- a/http.c
+++ b/http.c
@@ -1,8 +1,18 @@
 #include "http.h"
+#include "pack.h"
+#include "sideband.h"
 
 int data_received;
 int active_requests;
+int http_is_verbose;
+size_t http_post_buffer = 16 * LARGE_PACKET_MAX;
 
+#if LIBCURL_VERSION_NUM >= 0x070a06
+#define LIBCURL_CAN_HANDLE_AUTH_ANY
+#endif
+
+static int min_curl_sessions = 1;
+static int curl_session_count;
 #ifdef USE_CURL_MULTI
 static int max_requests = -1;
 static CURLM *curlm;
@@ -10,6 +20,10 @@ static CURLM *curlm;
 #ifndef NO_CURL_EASY_DUPHANDLE
 static CURL *curl_default;
 #endif
+
+#define PREV_BUF_SIZE 4096
+#define RANGE_HEADER_SIZE 30
+
 char curl_errorstr[CURL_ERROR_SIZE];
 
 static int curl_ssl_verify = -1;
@@ -27,7 +41,19 @@ static int curl_ftp_no_epsv;
 static const char *curl_http_proxy;
 static char *user_name, *user_pass;
 
+#if LIBCURL_VERSION_NUM >= 0x071700
+/* Use CURLOPT_KEYPASSWD as is */
+#elif LIBCURL_VERSION_NUM >= 0x070903
+#define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
+#else
+#define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
+#endif
+
+static char *ssl_cert_password;
+static int ssl_cert_password_required;
+
 static struct curl_slist *pragma_header;
+static struct curl_slist *no_pragma_header;
 
 static struct active_request_slot *active_queue_head;
 
@@ -79,8 +105,6 @@ size_t fwrite_null(const void *ptr, size_t eltsize, size_t nmemb, void *strbuf)
        return eltsize * nmemb;
 }
 
-static void finish_active_slot(struct active_request_slot *slot);
-
 #ifdef USE_CURL_MULTI
 static void process_curl_messages(void)
 {
@@ -129,6 +153,19 @@ static int http_options(const char *var, const char *value, void *cb)
 #endif
        if (!strcmp("http.sslcainfo", var))
                return git_config_string(&ssl_cainfo, var, value);
+       if (!strcmp("http.sslcertpasswordprotected", var)) {
+               if (git_config_bool(var, value))
+                       ssl_cert_password_required = 1;
+               return 0;
+       }
+       if (!strcmp("http.minsessions", var)) {
+               min_curl_sessions = git_config_int(var, value);
+#ifndef USE_CURL_MULTI
+               if (min_curl_sessions > 1)
+                       min_curl_sessions = 1;
+#endif
+               return 0;
+       }
 #ifdef USE_CURL_MULTI
        if (!strcmp("http.maxrequests", var)) {
                max_requests = git_config_int(var, value);
@@ -151,6 +188,13 @@ static int http_options(const char *var, const char *value, void *cb)
        if (!strcmp("http.proxy", var))
                return git_config_string(&curl_http_proxy, var, value);
 
+       if (!strcmp("http.postbuffer", var)) {
+               http_post_buffer = git_config_int(var, value);
+               if (http_post_buffer < LARGE_PACKET_MAX)
+                       http_post_buffer = LARGE_PACKET_MAX;
+               return 0;
+       }
+
        /* Fall back on the default ones */
        return git_default_config(var, value, cb);
 }
@@ -167,6 +211,22 @@ static void init_curl_http_auth(CURL *result)
        }
 }
 
+static int has_cert_password(void)
+{
+       if (ssl_cert_password != NULL)
+               return 1;
+       if (ssl_cert == NULL || ssl_cert_password_required != 1)
+               return 0;
+       /* Only prompt the user once. */
+       ssl_cert_password_required = -1;
+       ssl_cert_password = getpass("Certificate Password: ");
+       if (ssl_cert_password != NULL) {
+               ssl_cert_password = xstrdup(ssl_cert_password);
+               return 1;
+       } else
+               return 0;
+}
+
 static CURL *get_curl_handle(void)
 {
        CURL *result = curl_easy_init();
@@ -184,11 +244,16 @@ static CURL *get_curl_handle(void)
 #if LIBCURL_VERSION_NUM >= 0x070907
        curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 #endif
+#ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
+       curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
+#endif
 
        init_curl_http_auth(result);
 
        if (ssl_cert != NULL)
                curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
+       if (has_cert_password())
+               curl_easy_setopt(result, CURLOPT_KEYPASSWD, ssl_cert_password);
 #if LIBCURL_VERSION_NUM >= 0x070903
        if (ssl_key != NULL)
                curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
@@ -276,6 +341,8 @@ void http_init(struct remote *remote)
        char *low_speed_limit;
        char *low_speed_time;
 
+       http_is_verbose = 0;
+
        git_config(http_options, NULL);
 
        curl_global_init(CURL_GLOBAL_ALL);
@@ -284,6 +351,7 @@ void http_init(struct remote *remote)
                curl_http_proxy = xstrdup(remote->http_proxy);
 
        pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
+       no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
 
 #ifdef USE_CURL_MULTI
        {
@@ -321,6 +389,7 @@ void http_init(struct remote *remote)
        if (curl_ssl_verify == -1)
                curl_ssl_verify = 1;
 
+       curl_session_count = 0;
 #ifdef USE_CURL_MULTI
        if (max_requests < 1)
                max_requests = DEFAULT_MAX_REQUESTS;
@@ -329,8 +398,13 @@ void http_init(struct remote *remote)
        if (getenv("GIT_CURL_FTP_NO_EPSV"))
                curl_ftp_no_epsv = 1;
 
-       if (remote && remote->url && remote->url[0])
+       if (remote && remote->url && remote->url[0]) {
                http_auth_init(remote->url[0]);
+               if (!ssl_cert_password_required &&
+                   getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
+                   !prefixcmp(remote->url[0], "https://"))
+                       ssl_cert_password_required = 1;
+       }
 
 #ifndef NO_CURL_EASY_DUPHANDLE
        curl_default = get_curl_handle();
@@ -366,10 +440,20 @@ void http_cleanup(void)
        curl_slist_free_all(pragma_header);
        pragma_header = NULL;
 
+       curl_slist_free_all(no_pragma_header);
+       no_pragma_header = NULL;
+
        if (curl_http_proxy) {
                free((void *)curl_http_proxy);
                curl_http_proxy = NULL;
        }
+
+       if (ssl_cert_password != NULL) {
+               memset(ssl_cert_password, 0, strlen(ssl_cert_password));
+               free(ssl_cert_password);
+               ssl_cert_password = NULL;
+       }
+       ssl_cert_password_required = 0;
 }
 
 struct active_request_slot *get_active_slot(void)
@@ -414,6 +498,7 @@ struct active_request_slot *get_active_slot(void)
 #else
                slot->curl = curl_easy_duphandle(curl_default);
 #endif
+               curl_session_count++;
        }
 
        active_requests++;
@@ -492,9 +577,11 @@ void fill_active_slots(void)
        }
 
        while (slot != NULL) {
-               if (!slot->in_use && slot->curl != NULL) {
+               if (!slot->in_use && slot->curl != NULL
+                       && curl_session_count > min_curl_sessions) {
                        curl_easy_cleanup(slot->curl);
                        slot->curl = NULL;
+                       curl_session_count--;
                }
                slot = slot->next;
        }
@@ -564,22 +651,23 @@ static void closedown_active_slot(struct active_request_slot *slot)
        slot->in_use = 0;
 }
 
-void release_active_slot(struct active_request_slot *slot)
+static void release_active_slot(struct active_request_slot *slot)
 {
        closedown_active_slot(slot);
-       if (slot->curl) {
+       if (slot->curl && curl_session_count > min_curl_sessions) {
 #ifdef USE_CURL_MULTI
                curl_multi_remove_handle(curlm, slot->curl);
 #endif
                curl_easy_cleanup(slot->curl);
                slot->curl = NULL;
+               curl_session_count--;
        }
 #ifdef USE_CURL_MULTI
        fill_active_slots();
 #endif
 }
 
-static void finish_active_slot(struct active_request_slot *slot)
+void finish_active_slot(struct active_request_slot *slot)
 {
        closedown_active_slot(slot);
        curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
@@ -611,6 +699,7 @@ void finish_all_active_slots(void)
                }
 }
 
+/* Helpers for modifying and creating URLs */
 static inline int needs_quote(int ch)
 {
        if (((ch >= 'A') && (ch <= 'Z'))
@@ -631,15 +720,20 @@ static inline int hex(int v)
                return 'A' + v - 10;
 }
 
+static void end_url_with_slash(struct strbuf *buf, const char *url)
+{
+       strbuf_addstr(buf, url);
+       if (buf->len && buf->buf[buf->len - 1] != '/')
+               strbuf_addstr(buf, "/");
+}
+
 static char *quote_ref_url(const char *base, const char *ref)
 {
        struct strbuf buf = STRBUF_INIT;
        const char *cp;
        int ch;
 
-       strbuf_addstr(&buf, base);
-       if (buf.len && buf.buf[buf.len - 1] != '/' && *ref != '/')
-               strbuf_addstr(&buf, "/");
+       end_url_with_slash(&buf, base);
 
        for (cp = ref; (ch = *cp) != 0; cp++)
                if (needs_quote(ch))
@@ -650,41 +744,579 @@ static char *quote_ref_url(const char *base, const char *ref)
        return strbuf_detach(&buf, NULL);
 }
 
-int http_fetch_ref(const char *base, struct ref *ref)
+void append_remote_object_url(struct strbuf *buf, const char *url,
+                             const char *hex,
+                             int only_two_digit_prefix)
+{
+       end_url_with_slash(buf, url);
+
+       strbuf_addf(buf, "objects/%.*s/", 2, hex);
+       if (!only_two_digit_prefix)
+               strbuf_addf(buf, "%s", hex+2);
+}
+
+char *get_remote_object_url(const char *url, const char *hex,
+                           int only_two_digit_prefix)
+{
+       struct strbuf buf = STRBUF_INIT;
+       append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
+       return strbuf_detach(&buf, NULL);
+}
+
+/* http_request() targets */
+#define HTTP_REQUEST_STRBUF    0
+#define HTTP_REQUEST_FILE      1
+
+static int http_request(const char *url, void *result, int target, int options)
 {
-       char *url;
-       struct strbuf buffer = STRBUF_INIT;
        struct active_request_slot *slot;
        struct slot_results results;
+       struct curl_slist *headers = NULL;
+       struct strbuf buf = STRBUF_INIT;
        int ret;
 
-       url = quote_ref_url(base, ref->name);
        slot = get_active_slot();
        slot->results = &results;
-       curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
-       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
+       curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
+
+       if (result == NULL) {
+               curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
+       } else {
+               curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
+               curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
+
+               if (target == HTTP_REQUEST_FILE) {
+                       long posn = ftell(result);
+                       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
+                                        fwrite);
+                       if (posn > 0) {
+                               strbuf_addf(&buf, "Range: bytes=%ld-", posn);
+                               headers = curl_slist_append(headers, buf.buf);
+                               strbuf_reset(&buf);
+                       }
+                       slot->local = result;
+               } else
+                       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
+                                        fwrite_buffer);
+       }
+
+       strbuf_addstr(&buf, "Pragma:");
+       if (options & HTTP_NO_CACHE)
+               strbuf_addstr(&buf, " no-cache");
+
+       headers = curl_slist_append(headers, buf.buf);
+
        curl_easy_setopt(slot->curl, CURLOPT_URL, url);
+       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
+
        if (start_active_slot(slot)) {
                run_active_slot(slot);
-               if (results.curl_result == CURLE_OK) {
-                       strbuf_rtrim(&buffer);
-                       if (buffer.len == 40)
-                               ret = get_sha1_hex(buffer.buf, ref->old_sha1);
-                       else if (!prefixcmp(buffer.buf, "ref: ")) {
-                               ref->symref = xstrdup(buffer.buf + 5);
-                               ret = 0;
-                       } else
-                               ret = 1;
-               } else {
-                       ret = error("Couldn't get %s for %s\n%s",
-                                   url, ref->name, curl_errorstr);
-               }
+               if (results.curl_result == CURLE_OK)
+                       ret = HTTP_OK;
+               else if (missing_target(&results))
+                       ret = HTTP_MISSING_TARGET;
+               else
+                       ret = HTTP_ERROR;
        } else {
-               ret = error("Unable to start request");
+               error("Unable to start HTTP request for %s", url);
+               ret = HTTP_START_FAILED;
+       }
+
+       slot->local = NULL;
+       curl_slist_free_all(headers);
+       strbuf_release(&buf);
+
+       return ret;
+}
+
+int http_get_strbuf(const char *url, struct strbuf *result, int options)
+{
+       return http_request(url, result, HTTP_REQUEST_STRBUF, options);
+}
+
+/*
+ * Downloads an url and stores the result in the given file.
+ *
+ * If a previous interrupted download is detected (i.e. a previous temporary
+ * file is still around) the download is resumed.
+ */
+static int http_get_file(const char *url, const char *filename, int options)
+{
+       int ret;
+       struct strbuf tmpfile = STRBUF_INIT;
+       FILE *result;
+
+       strbuf_addf(&tmpfile, "%s.temp", filename);
+       result = fopen(tmpfile.buf, "a");
+       if (! result) {
+               error("Unable to open local file %s", tmpfile.buf);
+               ret = HTTP_ERROR;
+               goto cleanup;
+       }
+
+       ret = http_request(url, result, HTTP_REQUEST_FILE, options);
+       fclose(result);
+
+       if ((ret == HTTP_OK) && move_temp_to_file(tmpfile.buf, filename))
+               ret = HTTP_ERROR;
+cleanup:
+       strbuf_release(&tmpfile);
+       return ret;
+}
+
+int http_error(const char *url, int ret)
+{
+       /* http_request has already handled HTTP_START_FAILED. */
+       if (ret != HTTP_START_FAILED)
+               error("%s while accessing %s\n", curl_errorstr, url);
+
+       return ret;
+}
+
+int http_fetch_ref(const char *base, struct ref *ref)
+{
+       char *url;
+       struct strbuf buffer = STRBUF_INIT;
+       int ret = -1;
+
+       url = quote_ref_url(base, ref->name);
+       if (http_get_strbuf(url, &buffer, HTTP_NO_CACHE) == HTTP_OK) {
+               strbuf_rtrim(&buffer);
+               if (buffer.len == 40)
+                       ret = get_sha1_hex(buffer.buf, ref->old_sha1);
+               else if (!prefixcmp(buffer.buf, "ref: ")) {
+                       ref->symref = xstrdup(buffer.buf + 5);
+                       ret = 0;
+               }
        }
 
        strbuf_release(&buffer);
        free(url);
        return ret;
 }
+
+/* Helpers for fetching packs */
+static int fetch_pack_index(unsigned char *sha1, const char *base_url)
+{
+       int ret = 0;
+       char *hex = xstrdup(sha1_to_hex(sha1));
+       char *filename;
+       char *url = NULL;
+       struct strbuf buf = STRBUF_INIT;
+
+       if (has_pack_index(sha1)) {
+               ret = 0;
+               goto cleanup;
+       }
+
+       if (http_is_verbose)
+               fprintf(stderr, "Getting index for pack %s\n", hex);
+
+       end_url_with_slash(&buf, base_url);
+       strbuf_addf(&buf, "objects/pack/pack-%s.idx", hex);
+       url = strbuf_detach(&buf, NULL);
+
+       filename = sha1_pack_index_name(sha1);
+       if (http_get_file(url, filename, 0) != HTTP_OK)
+               ret = error("Unable to get pack index %s\n", url);
+
+cleanup:
+       free(hex);
+       free(url);
+       return ret;
+}
+
+static int fetch_and_setup_pack_index(struct packed_git **packs_head,
+       unsigned char *sha1, const char *base_url)
+{
+       struct packed_git *new_pack;
+
+       if (fetch_pack_index(sha1, base_url))
+               return -1;
+
+       new_pack = parse_pack_index(sha1);
+       if (!new_pack)
+               return -1; /* parse_pack_index() already issued error message */
+       new_pack->next = *packs_head;
+       *packs_head = new_pack;
+       return 0;
+}
+
+int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
+{
+       int ret = 0, i = 0;
+       char *url, *data;
+       struct strbuf buf = STRBUF_INIT;
+       unsigned char sha1[20];
+
+       end_url_with_slash(&buf, base_url);
+       strbuf_addstr(&buf, "objects/info/packs");
+       url = strbuf_detach(&buf, NULL);
+
+       ret = http_get_strbuf(url, &buf, HTTP_NO_CACHE);
+       if (ret != HTTP_OK)
+               goto cleanup;
+
+       data = buf.buf;
+       while (i < buf.len) {
+               switch (data[i]) {
+               case 'P':
+                       i++;
+                       if (i + 52 <= buf.len &&
+                           !prefixcmp(data + i, " pack-") &&
+                           !prefixcmp(data + i + 46, ".pack\n")) {
+                               get_sha1_hex(data + i + 6, sha1);
+                               fetch_and_setup_pack_index(packs_head, sha1,
+                                                     base_url);
+                               i += 51;
+                               break;
+                       }
+               default:
+                       while (i < buf.len && data[i] != '\n')
+                               i++;
+               }
+               i++;
+       }
+
+cleanup:
+       free(url);
+       return ret;
+}
+
+void release_http_pack_request(struct http_pack_request *preq)
+{
+       if (preq->packfile != NULL) {
+               fclose(preq->packfile);
+               preq->packfile = NULL;
+               preq->slot->local = NULL;
+       }
+       if (preq->range_header != NULL) {
+               curl_slist_free_all(preq->range_header);
+               preq->range_header = NULL;
+       }
+       preq->slot = NULL;
+       free(preq->url);
+}
+
+int finish_http_pack_request(struct http_pack_request *preq)
+{
+       int ret;
+       struct packed_git **lst;
+
+       preq->target->pack_size = ftell(preq->packfile);
+
+       if (preq->packfile != NULL) {
+               fclose(preq->packfile);
+               preq->packfile = NULL;
+               preq->slot->local = NULL;
+       }
+
+       ret = move_temp_to_file(preq->tmpfile, preq->filename);
+       if (ret)
+               return ret;
+
+       lst = preq->lst;
+       while (*lst != preq->target)
+               lst = &((*lst)->next);
+       *lst = (*lst)->next;
+
+       if (verify_pack(preq->target))
+               return -1;
+       install_packed_git(preq->target);
+
+       return 0;
+}
+
+struct http_pack_request *new_http_pack_request(
+       struct packed_git *target, const char *base_url)
+{
+       char *filename;
+       long prev_posn = 0;
+       char range[RANGE_HEADER_SIZE];
+       struct strbuf buf = STRBUF_INIT;
+       struct http_pack_request *preq;
+
+       preq = xmalloc(sizeof(*preq));
+       preq->target = target;
+       preq->range_header = NULL;
+
+       end_url_with_slash(&buf, base_url);
+       strbuf_addf(&buf, "objects/pack/pack-%s.pack",
+               sha1_to_hex(target->sha1));
+       preq->url = strbuf_detach(&buf, NULL);
+
+       filename = sha1_pack_name(target->sha1);
+       snprintf(preq->filename, sizeof(preq->filename), "%s", filename);
+       snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp", filename);
+       preq->packfile = fopen(preq->tmpfile, "a");
+       if (!preq->packfile) {
+               error("Unable to open local file %s for pack",
+                     preq->tmpfile);
+               goto abort;
+       }
+
+       preq->slot = get_active_slot();
+       preq->slot->local = preq->packfile;
+       curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
+       curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
+       curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
+       curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
+               no_pragma_header);
+
+       /*
+        * If there is data present from a previous transfer attempt,
+        * resume where it left off
+        */
+       prev_posn = ftell(preq->packfile);
+       if (prev_posn>0) {
+               if (http_is_verbose)
+                       fprintf(stderr,
+                               "Resuming fetch of pack %s at byte %ld\n",
+                               sha1_to_hex(target->sha1), prev_posn);
+               sprintf(range, "Range: bytes=%ld-", prev_posn);
+               preq->range_header = curl_slist_append(NULL, range);
+               curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
+                       preq->range_header);
+       }
+
+       return preq;
+
+abort:
+       free(filename);
+       free(preq->url);
+       free(preq);
+       return NULL;
+}
+
+/* Helpers for fetching objects (loose) */
+static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
+                              void *data)
+{
+       unsigned char expn[4096];
+       size_t size = eltsize * nmemb;
+       int posn = 0;
+       struct http_object_request *freq =
+               (struct http_object_request *)data;
+       do {
+               ssize_t retval = xwrite(freq->localfile,
+                                       (char *) ptr + posn, size - posn);
+               if (retval < 0)
+                       return posn;
+               posn += retval;
+       } while (posn < size);
+
+       freq->stream.avail_in = size;
+       freq->stream.next_in = ptr;
+       do {
+               freq->stream.next_out = expn;
+               freq->stream.avail_out = sizeof(expn);
+               freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
+               git_SHA1_Update(&freq->c, expn,
+                               sizeof(expn) - freq->stream.avail_out);
+       } while (freq->stream.avail_in && freq->zret == Z_OK);
+       data_received++;
+       return size;
+}
+
+struct http_object_request *new_http_object_request(const char *base_url,
+       unsigned char *sha1)
+{
+       char *hex = sha1_to_hex(sha1);
+       char *filename;
+       char prevfile[PATH_MAX];
+       int prevlocal;
+       unsigned char prev_buf[PREV_BUF_SIZE];
+       ssize_t prev_read = 0;
+       long prev_posn = 0;
+       char range[RANGE_HEADER_SIZE];
+       struct curl_slist *range_header = NULL;
+       struct http_object_request *freq;
+
+       freq = xmalloc(sizeof(*freq));
+       hashcpy(freq->sha1, sha1);
+       freq->localfile = -1;
+
+       filename = sha1_file_name(sha1);
+       snprintf(freq->filename, sizeof(freq->filename), "%s", filename);
+       snprintf(freq->tmpfile, sizeof(freq->tmpfile),
+                "%s.temp", filename);
+
+       snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
+       unlink_or_warn(prevfile);
+       rename(freq->tmpfile, prevfile);
+       unlink_or_warn(freq->tmpfile);
+
+       if (freq->localfile != -1)
+               error("fd leakage in start: %d", freq->localfile);
+       freq->localfile = open(freq->tmpfile,
+                              O_WRONLY | O_CREAT | O_EXCL, 0666);
+       /*
+        * This could have failed due to the "lazy directory creation";
+        * try to mkdir the last path component.
+        */
+       if (freq->localfile < 0 && errno == ENOENT) {
+               char *dir = strrchr(freq->tmpfile, '/');
+               if (dir) {
+                       *dir = 0;
+                       mkdir(freq->tmpfile, 0777);
+                       *dir = '/';
+               }
+               freq->localfile = open(freq->tmpfile,
+                                      O_WRONLY | O_CREAT | O_EXCL, 0666);
+       }
+
+       if (freq->localfile < 0) {
+               error("Couldn't create temporary file %s for %s: %s",
+                     freq->tmpfile, freq->filename, strerror(errno));
+               goto abort;
+       }
+
+       memset(&freq->stream, 0, sizeof(freq->stream));
+
+       git_inflate_init(&freq->stream);
+
+       git_SHA1_Init(&freq->c);
+
+       freq->url = get_remote_object_url(base_url, hex, 0);
+
+       /*
+        * If a previous temp file is present, process what was already
+        * fetched.
+        */
+       prevlocal = open(prevfile, O_RDONLY);
+       if (prevlocal != -1) {
+               do {
+                       prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
+                       if (prev_read>0) {
+                               if (fwrite_sha1_file(prev_buf,
+                                                    1,
+                                                    prev_read,
+                                                    freq) == prev_read) {
+                                       prev_posn += prev_read;
+                               } else {
+                                       prev_read = -1;
+                               }
+                       }
+               } while (prev_read > 0);
+               close(prevlocal);
+       }
+       unlink_or_warn(prevfile);
+
+       /*
+        * Reset inflate/SHA1 if there was an error reading the previous temp
+        * file; also rewind to the beginning of the local file.
+        */
+       if (prev_read == -1) {
+               memset(&freq->stream, 0, sizeof(freq->stream));
+               git_inflate_init(&freq->stream);
+               git_SHA1_Init(&freq->c);
+               if (prev_posn>0) {
+                       prev_posn = 0;
+                       lseek(freq->localfile, 0, SEEK_SET);
+                       if (ftruncate(freq->localfile, 0) < 0) {
+                               error("Couldn't truncate temporary file %s for %s: %s",
+                                         freq->tmpfile, freq->filename, strerror(errno));
+                               goto abort;
+                       }
+               }
+       }
+
+       freq->slot = get_active_slot();
+
+       curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
+       curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
+       curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
+       curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
+       curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
+
+       /*
+        * If we have successfully processed data from a previous fetch
+        * attempt, only fetch the data we don't already have.
+        */
+       if (prev_posn>0) {
+               if (http_is_verbose)
+                       fprintf(stderr,
+                               "Resuming fetch of object %s at byte %ld\n",
+                               hex, prev_posn);
+               sprintf(range, "Range: bytes=%ld-", prev_posn);
+               range_header = curl_slist_append(range_header, range);
+               curl_easy_setopt(freq->slot->curl,
+                                CURLOPT_HTTPHEADER, range_header);
+       }
+
+       return freq;
+
+abort:
+       free(filename);
+       free(freq->url);
+       free(freq);
+       return NULL;
+}
+
+void process_http_object_request(struct http_object_request *freq)
+{
+       if (freq->slot == NULL)
+               return;
+       freq->curl_result = freq->slot->curl_result;
+       freq->http_code = freq->slot->http_code;
+       freq->slot = NULL;
+}
+
+int finish_http_object_request(struct http_object_request *freq)
+{
+       struct stat st;
+
+       close(freq->localfile);
+       freq->localfile = -1;
+
+       process_http_object_request(freq);
+
+       if (freq->http_code == 416) {
+               warning("requested range invalid; we may already have all the data.");
+       } else if (freq->curl_result != CURLE_OK) {
+               if (stat(freq->tmpfile, &st) == 0)
+                       if (st.st_size == 0)
+                               unlink_or_warn(freq->tmpfile);
+               return -1;
+       }
+
+       git_inflate_end(&freq->stream);
+       git_SHA1_Final(freq->real_sha1, &freq->c);
+       if (freq->zret != Z_STREAM_END) {
+               unlink_or_warn(freq->tmpfile);
+               return -1;
+       }
+       if (hashcmp(freq->sha1, freq->real_sha1)) {
+               unlink_or_warn(freq->tmpfile);
+               return -1;
+       }
+       freq->rename =
+               move_temp_to_file(freq->tmpfile, freq->filename);
+
+       return freq->rename;
+}
+
+void abort_http_object_request(struct http_object_request *freq)
+{
+       unlink_or_warn(freq->tmpfile);
+
+       release_http_object_request(freq);
+}
+
+void release_http_object_request(struct http_object_request *freq)
+{
+       if (freq->localfile != -1) {
+               close(freq->localfile);
+               freq->localfile = -1;
+       }
+       if (freq->url != NULL) {
+               free(freq->url);
+               freq->url = NULL;
+       }
+       if (freq->slot != NULL) {
+               freq->slot->callback_func = NULL;
+               freq->slot->callback_data = NULL;
+               release_active_slot(freq->slot);
+               freq->slot = NULL;
+       }
+}