#include "cache.h"
#include "commit.h"
-#include "pack.h"
#include "walker.h"
#include "http.h"
-#define PREV_BUF_SIZE 4096
-#define RANGE_HEADER_SIZE 30
-
-struct alt_base
-{
+struct alt_base {
char *base;
int got_indices;
struct packed_git *packs;
WAITING,
ABORTED,
ACTIVE,
- COMPLETE,
+ COMPLETE
};
-struct object_request
-{
+struct object_request {
struct walker *walker;
unsigned char sha1[20];
struct alt_base *repo;
- char *url;
- char filename[PATH_MAX];
- char tmpfile[PATH_MAX];
- int local;
enum object_request_state state;
- CURLcode curl_result;
- char errorstr[CURL_ERROR_SIZE];
- long http_code;
- unsigned char real_sha1[20];
- git_SHA_CTX c;
- z_stream stream;
- int zret;
- int rename;
- struct active_request_slot *slot;
+ struct http_object_request *req;
struct object_request *next;
};
const char *url;
int got_alternates;
struct alt_base *alt;
- struct curl_slist *no_pragma_header;
};
static struct object_request *object_queue_head;
-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 object_request *obj_req = (struct object_request *)data;
- do {
- ssize_t retval = xwrite(obj_req->local,
- (char *) ptr + posn, size - posn);
- if (retval < 0)
- return posn;
- posn += retval;
- } while (posn < size);
-
- obj_req->stream.avail_in = size;
- obj_req->stream.next_in = ptr;
- do {
- obj_req->stream.next_out = expn;
- obj_req->stream.avail_out = sizeof(expn);
- obj_req->zret = git_inflate(&obj_req->stream, Z_SYNC_FLUSH);
- git_SHA1_Update(&obj_req->c, expn,
- sizeof(expn) - obj_req->stream.avail_out);
- } while (obj_req->stream.avail_in && obj_req->zret == Z_OK);
- data_received++;
- return size;
-}
-
static void fetch_alternates(struct walker *walker, const char *base);
static void process_object_response(void *callback_data);
static void start_object_request(struct walker *walker,
struct object_request *obj_req)
{
- char *hex = sha1_to_hex(obj_req->sha1);
- char prevfile[PATH_MAX];
- char *url;
- char *posn;
- 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 active_request_slot *slot;
- struct walker_data *data = walker->data;
-
- snprintf(prevfile, sizeof(prevfile), "%s.prev", obj_req->filename);
- unlink(prevfile);
- rename(obj_req->tmpfile, prevfile);
- unlink(obj_req->tmpfile);
-
- if (obj_req->local != -1)
- error("fd leakage in start: %d", obj_req->local);
- obj_req->local = open(obj_req->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 (obj_req->local < 0 && errno == ENOENT) {
- char *dir = strrchr(obj_req->tmpfile, '/');
- if (dir) {
- *dir = 0;
- mkdir(obj_req->tmpfile, 0777);
- *dir = '/';
- }
- obj_req->local = open(obj_req->tmpfile,
- O_WRONLY | O_CREAT | O_EXCL, 0666);
- }
+ struct http_object_request *req;
- if (obj_req->local < 0) {
+ req = new_http_object_request(obj_req->repo->base, obj_req->sha1);
+ if (req == NULL) {
obj_req->state = ABORTED;
- error("Couldn't create temporary file %s for %s: %s",
- obj_req->tmpfile, obj_req->filename, strerror(errno));
return;
}
+ obj_req->req = req;
- memset(&obj_req->stream, 0, sizeof(obj_req->stream));
-
- git_inflate_init(&obj_req->stream);
-
- git_SHA1_Init(&obj_req->c);
-
- url = xmalloc(strlen(obj_req->repo->base) + 51);
- obj_req->url = xmalloc(strlen(obj_req->repo->base) + 51);
- strcpy(url, obj_req->repo->base);
- posn = url + strlen(obj_req->repo->base);
- strcpy(posn, "/objects/");
- posn += 9;
- memcpy(posn, hex, 2);
- posn += 2;
- *(posn++) = '/';
- strcpy(posn, hex + 2);
- strcpy(obj_req->url, url);
-
- /* 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,
- obj_req) == prev_read) {
- prev_posn += prev_read;
- } else {
- prev_read = -1;
- }
- }
- } while (prev_read > 0);
- close(prevlocal);
- }
- unlink(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(&obj_req->stream, 0, sizeof(obj_req->stream));
- git_inflate_init(&obj_req->stream);
- git_SHA1_Init(&obj_req->c);
- if (prev_posn>0) {
- prev_posn = 0;
- lseek(obj_req->local, 0, SEEK_SET);
- ftruncate(obj_req->local, 0);
- }
- }
-
- slot = get_active_slot();
+ slot = req->slot;
slot->callback_func = process_object_response;
slot->callback_data = obj_req;
- obj_req->slot = slot;
-
- curl_easy_setopt(slot->curl, CURLOPT_FILE, obj_req);
- curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
- curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, obj_req->errorstr);
- curl_easy_setopt(slot->curl, CURLOPT_URL, url);
- curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, data->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 (walker->get_verbosely)
- 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(slot->curl,
- CURLOPT_HTTPHEADER, range_header);
- }
/* Try to get the request started, abort the request on error */
obj_req->state = ACTIVE;
if (!start_active_slot(slot)) {
obj_req->state = ABORTED;
- obj_req->slot = NULL;
- close(obj_req->local); obj_req->local = -1;
- free(obj_req->url);
+ release_http_object_request(req);
return;
}
}
static void finish_object_request(struct object_request *obj_req)
{
- struct stat st;
-
- close(obj_req->local); obj_req->local = -1;
-
- if (obj_req->http_code == 416) {
- fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
- } else if (obj_req->curl_result != CURLE_OK) {
- if (stat(obj_req->tmpfile, &st) == 0)
- if (st.st_size == 0)
- unlink(obj_req->tmpfile);
- return;
- }
-
- git_inflate_end(&obj_req->stream);
- git_SHA1_Final(obj_req->real_sha1, &obj_req->c);
- if (obj_req->zret != Z_STREAM_END) {
- unlink(obj_req->tmpfile);
- return;
- }
- if (hashcmp(obj_req->sha1, obj_req->real_sha1)) {
- unlink(obj_req->tmpfile);
+ if (finish_http_object_request(obj_req->req))
return;
- }
- obj_req->rename =
- move_temp_to_file(obj_req->tmpfile, obj_req->filename);
- if (obj_req->rename == 0)
+ if (obj_req->req->rename == 0)
walker_say(obj_req->walker, "got %s\n", sha1_to_hex(obj_req->sha1));
}
struct walker_data *data = walker->data;
struct alt_base *alt = data->alt;
- obj_req->curl_result = obj_req->slot->curl_result;
- obj_req->http_code = obj_req->slot->http_code;
- obj_req->slot = NULL;
+ process_http_object_request(obj_req->req);
obj_req->state = COMPLETE;
/* Use alternates if necessary */
- if (missing_target(obj_req)) {
+ if (missing_target(obj_req->req)) {
fetch_alternates(walker, alt->base);
if (obj_req->repo->next != NULL) {
obj_req->repo =
obj_req->repo->next;
- close(obj_req->local);
- obj_req->local = -1;
+ release_http_object_request(obj_req->req);
start_object_request(walker, obj_req);
return;
}
{
struct object_request *entry = object_queue_head;
- if (obj_req->local != -1)
- error("fd leakage in release: %d", obj_req->local);
+ if (obj_req->req !=NULL && obj_req->req->localfile != -1)
+ error("fd leakage in release: %d", obj_req->req->localfile);
if (obj_req == object_queue_head) {
object_queue_head = obj_req->next;
} else {
entry->next = entry->next->next;
}
- free(obj_req->url);
free(obj_req);
}
struct object_request *newreq;
struct object_request *tail;
struct walker_data *data = walker->data;
- char *filename = sha1_file_name(sha1);
newreq = xmalloc(sizeof(*newreq));
newreq->walker = walker;
hashcpy(newreq->sha1, sha1);
newreq->repo = data->alt;
- newreq->url = NULL;
- newreq->local = -1;
newreq->state = WAITING;
- snprintf(newreq->filename, sizeof(newreq->filename), "%s", filename);
- snprintf(newreq->tmpfile, sizeof(newreq->tmpfile),
- "%s.temp", filename);
- newreq->slot = NULL;
+ newreq->req = NULL;
newreq->next = NULL;
+ http_is_verbose = walker->get_verbosely;
+
if (object_queue_head == NULL) {
object_queue_head = newreq;
} else {
tail = object_queue_head;
- while (tail->next != NULL) {
+ while (tail->next != NULL)
tail = tail->next;
- }
tail->next = newreq;
}
#endif
}
-static int fetch_index(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
-{
- char *hex = sha1_to_hex(sha1);
- char *filename;
- char *url;
- char tmpfile[PATH_MAX];
- long prev_posn = 0;
- char range[RANGE_HEADER_SIZE];
- struct curl_slist *range_header = NULL;
- struct walker_data *data = walker->data;
-
- FILE *indexfile;
- struct active_request_slot *slot;
- struct slot_results results;
-
- if (has_pack_index(sha1))
- return 0;
-
- if (walker->get_verbosely)
- fprintf(stderr, "Getting index for pack %s\n", hex);
-
- url = xmalloc(strlen(repo->base) + 64);
- sprintf(url, "%s/objects/pack/pack-%s.idx", repo->base, hex);
-
- filename = sha1_pack_index_name(sha1);
- snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
- indexfile = fopen(tmpfile, "a");
- if (!indexfile)
- return error("Unable to open local file %s for pack index",
- tmpfile);
-
- slot = get_active_slot();
- slot->results = &results;
- curl_easy_setopt(slot->curl, CURLOPT_FILE, indexfile);
- curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
- curl_easy_setopt(slot->curl, CURLOPT_URL, url);
- curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, data->no_pragma_header);
- slot->local = indexfile;
-
- /* If there is data present from a previous transfer attempt,
- resume where it left off */
- prev_posn = ftell(indexfile);
- if (prev_posn>0) {
- if (walker->get_verbosely)
- fprintf(stderr,
- "Resuming fetch of index for pack %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(slot->curl, CURLOPT_HTTPHEADER, range_header);
- }
-
- if (start_active_slot(slot)) {
- run_active_slot(slot);
- if (results.curl_result != CURLE_OK) {
- fclose(indexfile);
- return error("Unable to get pack index %s\n%s", url,
- curl_errorstr);
- }
- } else {
- fclose(indexfile);
- return error("Unable to start request");
- }
-
- fclose(indexfile);
-
- return move_temp_to_file(tmpfile, filename);
-}
-
-static int setup_index(struct walker *walker, 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(walker, repo, sha1))
- return -1;
-
- new_pack = parse_pack_index(sha1);
- if (!new_pack)
- return -1; /* parse_pack_index() already issued error message */
- new_pack->next = repo->packs;
- repo->packs = new_pack;
- return 0;
-}
-
static void process_alternates_response(void *callback_data)
{
struct alternates_request *alt_req =
struct active_request_slot *slot = alt_req->slot;
struct alt_base *tail = cdata->alt;
const char *base = alt_req->base;
- static const char null_byte = '\0';
+ const char null_byte = '\0';
char *data;
int i = 0;
}
}
- fwrite_buffer(&null_byte, 1, 1, alt_req->buffer);
+ fwrite_buffer((char *)&null_byte, 1, 1, alt_req->buffer);
alt_req->buffer->len--;
data = alt_req->buffer->buf;
struct alt_base *newalt;
char *target = NULL;
if (data[i] == '/') {
- /* This counts
+ /*
+ * This counts
* http://git.host/pub/scm/linux.git/
* -----------here^
* so memcpy(dst, base, serverlen) will
okay = 1;
}
} else if (!memcmp(data + i, "../", 3)) {
- /* Relative URL; chop the corresponding
+ /*
+ * Relative URL; chop the corresponding
* number of subpath from base (and ../
* from data), and concatenate the result.
*
}
/* If the server got removed, give up. */
okay = strchr(base, ':') - base + 3 <
- serverlen;
+ serverlen;
} else if (alt_req->http_specific) {
char *colon = strchr(data + i, ':');
char *slash = strchr(data + i, '/');
struct alternates_request alt_req;
struct walker_data *cdata = walker->data;
- /* If another request has already started fetching alternates,
- wait for them to arrive and return to processing this request's
- curl message */
+ /*
+ * If another request has already started fetching alternates,
+ * wait for them to arrive and return to processing this request's
+ * curl message
+ */
#ifdef USE_CURL_MULTI
while (cdata->got_alternates == 0) {
step_active_slots();
url = xmalloc(strlen(base) + 31);
sprintf(url, "%s/objects/info/http-alternates", base);
- /* Use a callback to process the result, since another request
- may fail and need to have alternates loaded before continuing */
+ /*
+ * Use a callback to process the result, since another request
+ * may fail and need to have alternates loaded before continuing
+ */
slot = get_active_slot();
slot->callback_func = process_alternates_response;
alt_req.walker = walker;
static int fetch_indices(struct walker *walker, struct alt_base *repo)
{
- unsigned char sha1[20];
- char *url;
- struct strbuf buffer = STRBUF_INIT;
- char *data;
- int i = 0;
- int ret = 0;
-
- struct active_request_slot *slot;
- struct slot_results results;
+ int ret;
if (repo->got_indices)
return 0;
if (walker->get_verbosely)
fprintf(stderr, "Getting pack list for %s\n", repo->base);
- url = xmalloc(strlen(repo->base) + 21);
- sprintf(url, "%s/objects/info/packs", repo->base);
-
- 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_URL, url);
- curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
- if (start_active_slot(slot)) {
- run_active_slot(slot);
- if (results.curl_result != CURLE_OK) {
- if (missing_target(&results)) {
- repo->got_indices = 1;
- goto cleanup;
- } else {
- repo->got_indices = 0;
- ret = error("%s", curl_errorstr);
- goto cleanup;
- }
- }
- } else {
+ switch (http_get_info_packs(repo->base, &repo->packs)) {
+ case HTTP_OK:
+ case HTTP_MISSING_TARGET:
+ repo->got_indices = 1;
+ ret = 0;
+ break;
+ default:
repo->got_indices = 0;
- ret = error("Unable to start request");
- goto cleanup;
- }
-
- data = buffer.buf;
- while (i < buffer.len) {
- switch (data[i]) {
- case 'P':
- i++;
- if (i + 52 <= buffer.len &&
- !prefixcmp(data + i, " pack-") &&
- !prefixcmp(data + i + 46, ".pack\n")) {
- get_sha1_hex(data + i + 6, sha1);
- setup_index(walker, repo, sha1);
- i += 51;
- break;
- }
- default:
- while (i < buffer.len && data[i] != '\n')
- i++;
- }
- i++;
+ ret = -1;
}
- repo->got_indices = 1;
-cleanup:
- strbuf_release(&buffer);
- free(url);
return ret;
}
static int fetch_pack(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
{
- char *url;
struct packed_git *target;
- struct packed_git **lst;
- FILE *packfile;
- char *filename;
- char tmpfile[PATH_MAX];
int ret;
- long prev_posn = 0;
- char range[RANGE_HEADER_SIZE];
- struct curl_slist *range_header = NULL;
- struct walker_data *data = walker->data;
-
- struct active_request_slot *slot;
struct slot_results results;
+ struct http_pack_request *preq;
if (fetch_indices(walker, repo))
return -1;
sha1_to_hex(sha1));
}
- url = xmalloc(strlen(repo->base) + 65);
- sprintf(url, "%s/objects/pack/pack-%s.pack",
- repo->base, sha1_to_hex(target->sha1));
-
- filename = sha1_pack_name(target->sha1);
- snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
- packfile = fopen(tmpfile, "a");
- if (!packfile)
- return error("Unable to open local file %s for pack",
- tmpfile);
+ preq = new_http_pack_request(target, repo->base);
+ if (preq == NULL)
+ goto abort;
+ preq->lst = &repo->packs;
+ preq->slot->results = &results;
- slot = get_active_slot();
- slot->results = &results;
- curl_easy_setopt(slot->curl, CURLOPT_FILE, packfile);
- curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
- curl_easy_setopt(slot->curl, CURLOPT_URL, url);
- curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, data->no_pragma_header);
- slot->local = packfile;
-
- /* If there is data present from a previous transfer attempt,
- resume where it left off */
- prev_posn = ftell(packfile);
- if (prev_posn>0) {
- if (walker->get_verbosely)
- 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);
- range_header = curl_slist_append(range_header, range);
- curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
- }
-
- if (start_active_slot(slot)) {
- run_active_slot(slot);
+ if (start_active_slot(preq->slot)) {
+ run_active_slot(preq->slot);
if (results.curl_result != CURLE_OK) {
- fclose(packfile);
- return error("Unable to get pack file %s\n%s", url,
- curl_errorstr);
+ error("Unable to get pack file %s\n%s", preq->url,
+ curl_errorstr);
+ goto abort;
}
} else {
- fclose(packfile);
- return error("Unable to start request");
+ error("Unable to start request");
+ goto abort;
}
- target->pack_size = ftell(packfile);
- fclose(packfile);
-
- ret = move_temp_to_file(tmpfile, filename);
+ ret = finish_http_pack_request(preq);
+ release_http_pack_request(preq);
if (ret)
return ret;
- lst = &repo->packs;
- while (*lst != target)
- lst = &((*lst)->next);
- *lst = (*lst)->next;
-
- if (verify_pack(target))
- return -1;
- install_packed_git(target);
-
return 0;
+
+abort:
+ return -1;
}
static void abort_object_request(struct object_request *obj_req)
{
- if (obj_req->local >= 0) {
- close(obj_req->local);
- obj_req->local = -1;
- }
- unlink(obj_req->tmpfile);
- if (obj_req->slot) {
- release_active_slot(obj_req->slot);
- obj_req->slot = NULL;
- }
release_object_request(obj_req);
}
char *hex = sha1_to_hex(sha1);
int ret = 0;
struct object_request *obj_req = object_queue_head;
+ struct http_object_request *req;
while (obj_req != NULL && hashcmp(obj_req->sha1, sha1))
obj_req = obj_req->next;
return error("Couldn't find request for %s in the queue", hex);
if (has_sha1_file(obj_req->sha1)) {
+ if (obj_req->req != NULL)
+ abort_http_object_request(obj_req->req);
abort_object_request(obj_req);
return 0;
}
#ifdef USE_CURL_MULTI
- while (obj_req->state == WAITING) {
+ while (obj_req->state == WAITING)
step_active_slots();
- }
#else
start_object_request(walker, obj_req);
#endif
- while (obj_req->state == ACTIVE) {
- run_active_slot(obj_req->slot);
- }
- if (obj_req->local != -1) {
- close(obj_req->local); obj_req->local = -1;
+ /*
+ * obj_req->req might change when fetching alternates in the callback
+ * process_object_response; therefore, the "shortcut" variable, req,
+ * is used only after we're done with slots.
+ */
+ while (obj_req->state == ACTIVE)
+ run_active_slot(obj_req->req->slot);
+
+ req = obj_req->req;
+
+ if (req->localfile != -1) {
+ close(req->localfile);
+ req->localfile = -1;
}
if (obj_req->state == ABORTED) {
ret = error("Request for %s aborted", hex);
- } else if (obj_req->curl_result != CURLE_OK &&
- obj_req->http_code != 416) {
- if (missing_target(obj_req))
+ } else if (req->curl_result != CURLE_OK &&
+ req->http_code != 416) {
+ if (missing_target(req))
ret = -1; /* Be silent, it is probably in a pack. */
else
ret = error("%s (curl_result = %d, http_code = %ld, sha1 = %s)",
- obj_req->errorstr, obj_req->curl_result,
- obj_req->http_code, hex);
- } else if (obj_req->zret != Z_STREAM_END) {
+ req->errorstr, req->curl_result,
+ req->http_code, hex);
+ } else if (req->zret != Z_STREAM_END) {
walker->corrupt_object_found++;
- ret = error("File %s (%s) corrupt", hex, obj_req->url);
- } else if (hashcmp(obj_req->sha1, obj_req->real_sha1)) {
+ ret = error("File %s (%s) corrupt", hex, req->url);
+ } else if (hashcmp(obj_req->sha1, req->real_sha1)) {
ret = error("File %s has bad hash", hex);
- } else if (obj_req->rename < 0) {
+ } else if (req->rename < 0) {
ret = error("unable to write sha1 filename %s",
- obj_req->filename);
+ sha1_file_name(req->sha1));
}
+ release_http_object_request(req);
release_object_request(obj_req);
return ret;
}
static void cleanup(struct walker *walker)
{
struct walker_data *data = walker->data;
- http_cleanup();
+ struct alt_base *alt, *alt_next;
+
+ if (data) {
+ alt = data->alt;
+ while (alt) {
+ alt_next = alt->next;
- curl_slist_free_all(data->no_pragma_header);
+ free(alt->base);
+ free(alt);
+
+ alt = alt_next;
+ }
+ free(data);
+ walker->data = NULL;
+ }
}
-struct walker *get_http_walker(const char *url, struct remote *remote)
+struct walker *get_http_walker(const char *url)
{
char *s;
struct walker_data *data = xmalloc(sizeof(struct walker_data));
struct walker *walker = xmalloc(sizeof(struct walker));
- http_init(remote);
-
- data->no_pragma_header = curl_slist_append(NULL, "Pragma:");
-
data->alt = xmalloc(sizeof(*data->alt));
data->alt->base = xmalloc(strlen(url) + 1);
strcpy(data->alt->base, url);