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mbuf.h
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1 /*
2  * mbuf.h
3  * Memory buffer operations.
4  *
5  * Copyright (c) 2005 Marko Kreen
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  * notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  * notice, this list of conditions and the following disclaimer in the
15  * documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * contrib/pgcrypto/mbuf.h
30  */
31 
32 #ifndef __PX_MBUF_H
33 #define __PX_MBUF_H
34 
35 typedef struct MBuf MBuf;
36 typedef struct PushFilter PushFilter;
37 typedef struct PullFilter PullFilter;
38 typedef struct PushFilterOps PushFilterOps;
39 typedef struct PullFilterOps PullFilterOps;
40 
42 {
43  /*
44  * should return needed buffer size, 0- no buffering, <0 on error if NULL,
45  * no buffering, and priv=init_arg
46  */
47  int (*init) (PushFilter *next, void *init_arg, void **priv_p);
48 
49  /*
50  * send data to next. should consume all? if null, it will be simply
51  * copied (in-place) returns 0 on error
52  */
53  int (*push) (PushFilter *next, void *priv,
54  const uint8 *src, int len);
55  int (*flush) (PushFilter *next, void *priv);
56  void (*free) (void *priv);
57 };
58 
60 {
61  /*
62  * should return needed buffer size, 0- no buffering, <0 on error if NULL,
63  * no buffering, and priv=init_arg
64  */
65  int (*init) (void **priv_p, void *init_arg, PullFilter *src);
66 
67  /*
68  * request data from src, put result ptr to data_p can use ptr from src or
69  * use buf as work area if NULL in-place copy
70  */
71  int (*pull) (void *priv, PullFilter *src, int len,
72  uint8 **data_p, uint8 *buf, int buflen);
73  void (*free) (void *priv);
74 };
75 
76 /*
77  * Memory buffer
78  */
79 MBuf *mbuf_create(int len);
81 int mbuf_avail(MBuf *mbuf);
82 int mbuf_size(MBuf *mbuf);
83 int mbuf_grab(MBuf *mbuf, int len, uint8 **data_p);
84 int mbuf_steal_data(MBuf *mbuf, uint8 **data_p);
85 int mbuf_append(MBuf *dst, const uint8 *buf, int len);
86 int mbuf_free(MBuf *mbuf);
87 
88 /*
89  * Push filter
90  */
91 int pushf_create(PushFilter **mp_p, const PushFilterOps *op,
92  void *init_arg, PushFilter *next);
93 int pushf_write(PushFilter *mp, const uint8 *data, int len);
94 void pushf_free_all(PushFilter *mp);
95 void pushf_free(PushFilter *mp);
96 int pushf_flush(PushFilter *mp);
97 
99 
100 /*
101  * Pull filter
102  */
103 int pullf_create(PullFilter **pf_p, const PullFilterOps *op,
104  void *init_arg, PullFilter *src);
105 int pullf_read(PullFilter *pf, int len, uint8 **data_p);
106 int pullf_read_max(PullFilter *pf, int len,
107  uint8 **data_p, uint8 *tmpbuf);
108 void pullf_free(PullFilter *pf);
109 int pullf_read_fixed(PullFilter *src, int len, uint8 *dst);
110 
111 int pullf_create_mbuf_reader(PullFilter **mp_p, MBuf *src);
112 
113 #define GETBYTE(pf, dst) \
114  do { \
115  uint8 __b; \
116  int __res = pullf_read_fixed(pf, 1, &__b); \
117  if (__res < 0) \
118  return __res; \
119  (dst) = __b; \
120  } while (0)
121 
122 #endif /* __PX_MBUF_H */
static int32 next
Definition: blutils.c:219
unsigned char uint8
Definition: c.h:516
MBuf * mbuf_create_from_data(uint8 *data, int len)
Definition: mbuf.c:131
int pullf_read_fixed(PullFilter *src, int len, uint8 *dst)
Definition: mbuf.c:301
int pullf_create(PullFilter **pf_p, const PullFilterOps *op, void *init_arg, PullFilter *src)
Definition: mbuf.c:191
int pushf_write(PushFilter *mp, const uint8 *data, int len)
Definition: mbuf.c:439
int mbuf_avail(MBuf *mbuf)
Definition: mbuf.c:50
int pushf_create(PushFilter **mp_p, const PushFilterOps *op, void *init_arg, PushFilter *next)
Definition: mbuf.c:357
int pullf_read_max(PullFilter *pf, int len, uint8 **data_p, uint8 *tmpbuf)
Definition: mbuf.c:263
int mbuf_free(MBuf *mbuf)
Definition: mbuf.c:62
int pullf_create_mbuf_reader(PullFilter **mp_p, MBuf *src)
Definition: mbuf.c:336
int mbuf_append(MBuf *dst, const uint8 *buf, int len)
Definition: mbuf.c:94
int pullf_read(PullFilter *pf, int len, uint8 **data_p)
Definition: mbuf.c:246
int pushf_create_mbuf_writer(PushFilter **res, MBuf *dst)
Definition: mbuf.c:544
int mbuf_steal_data(MBuf *mbuf, uint8 **data_p)
Definition: mbuf.c:162
void pushf_free_all(PushFilter *mp)
Definition: mbuf.c:411
int pushf_flush(PushFilter *mp)
Definition: mbuf.c:499
int mbuf_size(MBuf *mbuf)
Definition: mbuf.c:56
int mbuf_grab(MBuf *mbuf, int len, uint8 **data_p)
Definition: mbuf.c:149
void pushf_free(PushFilter *mp)
Definition: mbuf.c:395
void pullf_free(PullFilter *pf)
Definition: mbuf.c:229
MBuf * mbuf_create(int len)
Definition: mbuf.c:111
const void size_t len
const void * data
static char * buf
Definition: pg_test_fsync.c:72
Definition: mbuf.c:40
void(* free)(void *priv)
Definition: mbuf.h:73
int(* init)(void **priv_p, void *init_arg, PullFilter *src)
Definition: mbuf.h:65
int(* pull)(void *priv, PullFilter *src, int len, uint8 **data_p, uint8 *buf, int buflen)
Definition: mbuf.h:71
int(* flush)(PushFilter *next, void *priv)
Definition: mbuf.h:55
void(* free)(void *priv)
Definition: mbuf.h:56
int(* init)(PushFilter *next, void *init_arg, void **priv_p)
Definition: mbuf.h:47
int(* push)(PushFilter *next, void *priv, const uint8 *src, int len)
Definition: mbuf.h:53
static StringInfoData tmpbuf
Definition: walsender.c:170