git/http.h
Junio C Hamano ef49a7a012 zlib: zlib can only process 4GB at a time
The size of objects we read from the repository and data we try to put
into the repository are represented in "unsigned long", so that on larger
architectures we can handle objects that weigh more than 4GB.

But the interface defined in zlib.h to communicate with inflate/deflate
limits avail_in (how many bytes of input are we calling zlib with) and
avail_out (how many bytes of output from zlib are we ready to accept)
fields effectively to 4GB by defining their type to be uInt.

In many places in our code, we allocate a large buffer (e.g. mmap'ing a
large loose object file) and tell zlib its size by assigning the size to
avail_in field of the stream, but that will truncate the high octets of
the real size. The worst part of this story is that we often pass around
z_stream (the state object used by zlib) to keep track of the number of
used bytes in input/output buffer by inspecting these two fields, which
practically limits our callchain to the same 4GB limit.

Wrap z_stream in another structure git_zstream that can express avail_in
and avail_out in unsigned long. For now, just die() when the caller gives
a size that cannot be given to a single zlib call. In later patches in the
series, we would make git_inflate() and git_deflate() internally loop to
give callers an illusion that our "improved" version of zlib interface can
operate on a buffer larger than 4GB in one go.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-06-10 11:52:15 -07:00

189 lines
5.1 KiB
C

#ifndef HTTP_H
#define HTTP_H
#include "cache.h"
#include <curl/curl.h>
#include <curl/easy.h>
#include "strbuf.h"
#include "remote.h"
#include "url.h"
/*
* We detect based on the cURL version if multi-transfer is
* usable in this implementation and define this symbol accordingly.
* This is not something Makefile should set nor users should pass
* via CFLAGS.
*/
#undef USE_CURL_MULTI
#if LIBCURL_VERSION_NUM >= 0x071000
#define USE_CURL_MULTI
#define DEFAULT_MAX_REQUESTS 5
#endif
#if LIBCURL_VERSION_NUM < 0x070704
#define curl_global_cleanup() do { /* nothing */ } while (0)
#endif
#if LIBCURL_VERSION_NUM < 0x070800
#define curl_global_init(a) do { /* nothing */ } while (0)
#endif
#if (LIBCURL_VERSION_NUM < 0x070c04) || (LIBCURL_VERSION_NUM == 0x071000)
#define NO_CURL_EASY_DUPHANDLE
#endif
#if LIBCURL_VERSION_NUM < 0x070a03
#define CURLE_HTTP_RETURNED_ERROR CURLE_HTTP_NOT_FOUND
#endif
#if LIBCURL_VERSION_NUM < 0x070c03
#define NO_CURL_IOCTL
#endif
struct slot_results {
CURLcode curl_result;
long http_code;
};
struct active_request_slot {
CURL *curl;
FILE *local;
int in_use;
CURLcode curl_result;
long http_code;
int *finished;
struct slot_results *results;
void *callback_data;
void (*callback_func)(void *data);
struct active_request_slot *next;
};
struct buffer {
struct strbuf buf;
size_t posn;
};
/* Curl request read/write callbacks */
extern size_t fread_buffer(void *ptr, size_t eltsize, size_t nmemb, void *strbuf);
extern size_t fwrite_buffer(const void *ptr, size_t eltsize, size_t nmemb, void *strbuf);
extern size_t fwrite_null(const void *ptr, size_t eltsize, size_t nmemb, void *strbuf);
#ifndef NO_CURL_IOCTL
extern curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp);
#endif
/* Slot lifecycle functions */
extern struct active_request_slot *get_active_slot(void);
extern int start_active_slot(struct active_request_slot *slot);
extern void run_active_slot(struct active_request_slot *slot);
extern void finish_active_slot(struct active_request_slot *slot);
extern void finish_all_active_slots(void);
#ifdef USE_CURL_MULTI
extern void fill_active_slots(void);
extern void add_fill_function(void *data, int (*fill)(void *));
extern void step_active_slots(void);
#endif
extern void http_init(struct remote *remote);
extern void http_cleanup(void);
extern int data_received;
extern int active_requests;
extern int http_is_verbose;
extern size_t http_post_buffer;
extern char curl_errorstr[CURL_ERROR_SIZE];
static inline int missing__target(int code, int result)
{
return /* file:// URL -- do we ever use one??? */
(result == CURLE_FILE_COULDNT_READ_FILE) ||
/* http:// and https:// URL */
(code == 404 && result == CURLE_HTTP_RETURNED_ERROR) ||
/* ftp:// URL */
(code == 550 && result == CURLE_FTP_COULDNT_RETR_FILE)
;
}
#define missing_target(a) missing__target((a)->http_code, (a)->curl_result)
/* Helpers for modifying and creating URLs */
extern void append_remote_object_url(struct strbuf *buf, const char *url,
const char *hex,
int only_two_digit_prefix);
extern char *get_remote_object_url(const char *url, const char *hex,
int only_two_digit_prefix);
/* Options for http_request_*() */
#define HTTP_NO_CACHE 1
/* Return values for http_request_*() */
#define HTTP_OK 0
#define HTTP_MISSING_TARGET 1
#define HTTP_ERROR 2
#define HTTP_START_FAILED 3
#define HTTP_REAUTH 4
#define HTTP_NOAUTH 5
/*
* Requests an url and stores the result in a strbuf.
*
* If the result pointer is NULL, a HTTP HEAD request is made instead of GET.
*/
int http_get_strbuf(const char *url, struct strbuf *result, int options);
/*
* Prints an error message using error() containing url and curl_errorstr,
* and returns ret.
*/
int http_error(const char *url, int ret);
extern int http_fetch_ref(const char *base, struct ref *ref);
/* Helpers for fetching packs */
extern int http_get_info_packs(const char *base_url,
struct packed_git **packs_head);
struct http_pack_request {
char *url;
struct packed_git *target;
struct packed_git **lst;
FILE *packfile;
char tmpfile[PATH_MAX];
struct curl_slist *range_header;
struct active_request_slot *slot;
};
extern struct http_pack_request *new_http_pack_request(
struct packed_git *target, const char *base_url);
extern int finish_http_pack_request(struct http_pack_request *preq);
extern void release_http_pack_request(struct http_pack_request *preq);
/* Helpers for fetching object */
struct http_object_request {
char *url;
char tmpfile[PATH_MAX];
int localfile;
CURLcode curl_result;
char errorstr[CURL_ERROR_SIZE];
long http_code;
unsigned char sha1[20];
unsigned char real_sha1[20];
git_SHA_CTX c;
git_zstream stream;
int zret;
int rename;
struct active_request_slot *slot;
};
extern struct http_object_request *new_http_object_request(
const char *base_url, unsigned char *sha1);
extern void process_http_object_request(struct http_object_request *freq);
extern int finish_http_object_request(struct http_object_request *freq);
extern void abort_http_object_request(struct http_object_request *freq);
extern void release_http_object_request(struct http_object_request *freq);
#endif /* HTTP_H */