view mercurial/thirdparty/xdiff/xdiff.h @ 37047:fddcb51b5084

wireproto: define permissions-based routing of HTTPv2 wire protocol

Now that we have a scaffolding for serving version 2 of the HTTP
protocol, let's start implementing it.

A good place to start is URL routing and basic request processing
semantics. We can focus on content types, capabilities detect, etc
later.

Version 2 of the HTTP wire protocol encodes the needed permissions
of the request in the URL path. The reasons for this are documented
in the added documentation. In short, a) it makes it really easy and
fail proof for server administrators to implement path-based
authentication and b) it will enable clients to realize very early in
a server exchange that authentication will be required to complete
the operation. This latter point avoids all kinds of complexity and
problems, like dealing with Expect: 100-continue and clients finding
out later during `hg push` that they need to provide authentication.
This will avoid the current badness where clients send a full bundle,
get an HTTP 403, provide authentication, then retransmit the bundle.

In order to implement command checking, we needed to implement a
protocol handler for the new wire protocol. Our handler is just
small enough to run the code we've implemented.

Tests for the defined functionality have been added.

I very much want to refactor the permissions checking code and define
a better response format. But this can be done later. Nothing is
covered by backwards compatibility at this point.

Differential Revision: https://phab.mercurial-scm.org/D2836

/*
 *  LibXDiff by Davide Libenzi ( File Differential Library )
 *  Copyright (C) 2003  Davide Libenzi
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, see
 *  <http://www.gnu.org/licenses/>.
 *
 *  Davide Libenzi <[e-mail]>
 *
 */

#if !defined(XDIFF_H)
#define XDIFF_H

#ifdef __cplusplus
extern "C" {
#endif /* #ifdef __cplusplus */

#include <stddef.h> /* size_t */

#if !defined(_MSC_VER) || _MSC_VER >= 1600
#include <stdint.h>
#else
/* prior to Visual Studio 2010 */
typedef long long int64_t;
typedef unsigned long long uint64_t;
#endif

/* xpparm_t.flags */
#define XDF_NEED_MINIMAL (1 << 0)

#define XDF_INDENT_HEURISTIC (1 << 23)

/* emit bdiff-style "matched" (a1, a2, b1, b2) hunks instead of "different"
 * (a1, a2 - a1, b1, b2 - b1) hunks */
#define XDL_EMIT_BDIFFHUNK (1 << 4)

typedef struct s_mmfile {
	char *ptr;
	int64_t size;
} mmfile_t;

typedef struct s_mmbuffer {
	char *ptr;
	int64_t size;
} mmbuffer_t;

typedef struct s_xpparam {
	uint64_t flags;
} xpparam_t;

typedef struct s_xdemitcb {
	void *priv;
} xdemitcb_t;

typedef int (*xdl_emit_hunk_consume_func_t)(int64_t start_a, int64_t count_a,
					    int64_t start_b, int64_t count_b,
					    void *cb_data);

typedef struct s_xdemitconf {
	uint64_t flags;
	xdl_emit_hunk_consume_func_t hunk_func;
} xdemitconf_t;


#define xdl_malloc(x) malloc(x)
#define xdl_free(ptr) free(ptr)
#define xdl_realloc(ptr,x) realloc(ptr,x)

void *xdl_mmfile_first(mmfile_t *mmf, int64_t *size);
int64_t xdl_mmfile_size(mmfile_t *mmf);

int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
	     xdemitconf_t const *xecfg, xdemitcb_t *ecb);

#ifdef __cplusplus
}
#endif /* #ifdef __cplusplus */

#endif /* #if !defined(XDIFF_H) */