mirror of
https://github.com/git/git
synced 2024-08-28 20:20:07 +00:00
![Jeff King](/assets/img/avatar_default.png)
We currently don't reuse http connections when fetching via the smart-http protocol. This is bad because the TCP handshake introduces latency, and especially because SSL connection setup may be non-trivial. We can fix it by consistently using curl's "multi" interface. The reason is rather complicated: Our http code has two ways of being used: queuing many "slots" to be fetched in parallel, or fetching a single request in a blocking manner. The parallel code is built on curl's "multi" interface. Most of the single-request code uses http_request, which is built on top of the parallel code (we just feed it one slot, and wait until it finishes). However, one could also accomplish the single-request scheme by avoiding curl's multi interface entirely and just using curl_easy_perform. This is simpler, and is used by post_rpc in the smart-http protocol. It does work to use the same curl handle in both contexts, as long as it is not at the same time. However, internally curl may not share all of the cached resources between both contexts. In particular, a connection formed using the "multi" code will go into a reuse pool connected to the "multi" object. Further requests using the "easy" interface will not be able to reuse that connection. The smart http protocol does ref discovery via http_request, which uses the "multi" interface, and then follows up with the "easy" interface for its rpc calls. As a result, we make two HTTP connections rather than reusing a single one. We could teach the ref discovery to use the "easy" interface. But it is only once we have done this discovery that we know whether the protocol will be smart or dumb. If it is dumb, then our further requests, which want to fetch objects in parallel, will not be able to reuse the same connection. Instead, this patch switches post_rpc to build on the parallel interface, which means that we use it consistently everywhere. It's a little more complicated to use, but since we have the infrastructure already, it doesn't add any code; we can just factor out the relevant bits from http_request. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
223 lines
6.1 KiB
C
223 lines
6.1 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
|
|
|
|
/*
|
|
* CURLOPT_USE_SSL was known as CURLOPT_FTP_SSL up to 7.16.4,
|
|
* and the constants were known as CURLFTPSSL_*
|
|
*/
|
|
#if !defined(CURLOPT_USE_SSL) && defined(CURLOPT_FTP_SSL)
|
|
#define CURLOPT_USE_SSL CURLOPT_FTP_SSL
|
|
#define CURLUSESSL_TRY CURLFTPSSL_TRY
|
|
#endif
|
|
|
|
struct slot_results {
|
|
CURLcode curl_result;
|
|
long http_code;
|
|
long auth_avail;
|
|
};
|
|
|
|
struct active_request_slot {
|
|
CURL *curl;
|
|
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(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
|
|
extern size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
|
|
extern size_t fwrite_null(char *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);
|
|
extern int handle_curl_result(struct slot_results *results);
|
|
|
|
/*
|
|
* This will run one slot to completion in a blocking manner, similar to how
|
|
* curl_easy_perform would work (but we don't want to use that, because
|
|
* we do not want to intermingle calls to curl_multi and curl_easy).
|
|
*
|
|
*/
|
|
int run_one_slot(struct active_request_slot *slot,
|
|
struct slot_results *results);
|
|
|
|
#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, const char *url,
|
|
int proactive_auth);
|
|
extern void http_cleanup(void);
|
|
|
|
extern int active_requests;
|
|
extern int http_is_verbose;
|
|
extern size_t http_post_buffer;
|
|
extern struct credential http_auth;
|
|
|
|
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_get_*() */
|
|
struct http_get_options {
|
|
unsigned no_cache:1,
|
|
keep_error:1;
|
|
|
|
/* If non-NULL, returns the content-type of the response. */
|
|
struct strbuf *content_type;
|
|
|
|
/*
|
|
* If non-NULL, returns the URL we ended up at, including any
|
|
* redirects we followed.
|
|
*/
|
|
struct strbuf *effective_url;
|
|
|
|
/*
|
|
* If both base_url and effective_url are non-NULL, the base URL will
|
|
* be munged to reflect any redirections going from the requested url
|
|
* to effective_url. See the definition of update_url_from_redirect
|
|
* for details.
|
|
*/
|
|
struct strbuf *base_url;
|
|
};
|
|
|
|
/* Return values for http_get_*() */
|
|
#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 a 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, struct http_get_options *options);
|
|
|
|
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 */
|