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Commit | Line | Data |
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8efc0c15 | 1 | /* |
5260325f | 2 | * |
3 | * buffer.c | |
4 | * | |
5 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | |
6 | * | |
7 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
8 | * All rights reserved | |
9 | * | |
10 | * Created: Sat Mar 18 04:15:33 1995 ylo | |
11 | * | |
12 | * Functions for manipulating fifo buffers (that can grow if needed). | |
13 | * | |
14 | */ | |
8efc0c15 | 15 | |
16 | #include "includes.h" | |
17 | RCSID("$Id$"); | |
18 | ||
19 | #include "xmalloc.h" | |
20 | #include "buffer.h" | |
21 | #include "ssh.h" | |
22 | ||
23 | /* Initializes the buffer structure. */ | |
24 | ||
5260325f | 25 | void |
26 | buffer_init(Buffer *buffer) | |
8efc0c15 | 27 | { |
5260325f | 28 | buffer->alloc = 4096; |
29 | buffer->buf = xmalloc(buffer->alloc); | |
30 | buffer->offset = 0; | |
31 | buffer->end = 0; | |
8efc0c15 | 32 | } |
33 | ||
34 | /* Frees any memory used for the buffer. */ | |
35 | ||
5260325f | 36 | void |
37 | buffer_free(Buffer *buffer) | |
8efc0c15 | 38 | { |
5260325f | 39 | memset(buffer->buf, 0, buffer->alloc); |
40 | xfree(buffer->buf); | |
8efc0c15 | 41 | } |
42 | ||
43 | /* Clears any data from the buffer, making it empty. This does not actually | |
44 | zero the memory. */ | |
45 | ||
5260325f | 46 | void |
47 | buffer_clear(Buffer *buffer) | |
8efc0c15 | 48 | { |
5260325f | 49 | buffer->offset = 0; |
50 | buffer->end = 0; | |
8efc0c15 | 51 | } |
52 | ||
53 | /* Appends data to the buffer, expanding it if necessary. */ | |
54 | ||
5260325f | 55 | void |
56 | buffer_append(Buffer *buffer, const char *data, unsigned int len) | |
8efc0c15 | 57 | { |
5260325f | 58 | char *cp; |
59 | buffer_append_space(buffer, &cp, len); | |
60 | memcpy(cp, data, len); | |
8efc0c15 | 61 | } |
62 | ||
63 | /* Appends space to the buffer, expanding the buffer if necessary. | |
64 | This does not actually copy the data into the buffer, but instead | |
65 | returns a pointer to the allocated region. */ | |
66 | ||
5260325f | 67 | void |
68 | buffer_append_space(Buffer *buffer, char **datap, unsigned int len) | |
8efc0c15 | 69 | { |
5260325f | 70 | /* If the buffer is empty, start using it from the beginning. */ |
71 | if (buffer->offset == buffer->end) { | |
72 | buffer->offset = 0; | |
73 | buffer->end = 0; | |
74 | } | |
75 | restart: | |
76 | /* If there is enough space to store all data, store it now. */ | |
77 | if (buffer->end + len < buffer->alloc) { | |
78 | *datap = buffer->buf + buffer->end; | |
79 | buffer->end += len; | |
80 | return; | |
81 | } | |
82 | /* If the buffer is quite empty, but all data is at the end, move | |
83 | the data to the beginning and retry. */ | |
84 | if (buffer->offset > buffer->alloc / 2) { | |
85 | memmove(buffer->buf, buffer->buf + buffer->offset, | |
86 | buffer->end - buffer->offset); | |
87 | buffer->end -= buffer->offset; | |
88 | buffer->offset = 0; | |
89 | goto restart; | |
90 | } | |
91 | /* Increase the size of the buffer and retry. */ | |
92 | buffer->alloc += len + 32768; | |
93 | buffer->buf = xrealloc(buffer->buf, buffer->alloc); | |
94 | goto restart; | |
8efc0c15 | 95 | } |
96 | ||
97 | /* Returns the number of bytes of data in the buffer. */ | |
98 | ||
5260325f | 99 | unsigned int |
100 | buffer_len(Buffer *buffer) | |
8efc0c15 | 101 | { |
5260325f | 102 | return buffer->end - buffer->offset; |
8efc0c15 | 103 | } |
104 | ||
105 | /* Gets data from the beginning of the buffer. */ | |
106 | ||
5260325f | 107 | void |
108 | buffer_get(Buffer *buffer, char *buf, unsigned int len) | |
8efc0c15 | 109 | { |
5260325f | 110 | if (len > buffer->end - buffer->offset) |
111 | fatal("buffer_get trying to get more bytes than in buffer"); | |
112 | memcpy(buf, buffer->buf + buffer->offset, len); | |
113 | buffer->offset += len; | |
8efc0c15 | 114 | } |
115 | ||
116 | /* Consumes the given number of bytes from the beginning of the buffer. */ | |
117 | ||
5260325f | 118 | void |
119 | buffer_consume(Buffer *buffer, unsigned int bytes) | |
8efc0c15 | 120 | { |
5260325f | 121 | if (bytes > buffer->end - buffer->offset) |
122 | fatal("buffer_get trying to get more bytes than in buffer"); | |
123 | buffer->offset += bytes; | |
124 | } | |
8efc0c15 | 125 | |
126 | /* Consumes the given number of bytes from the end of the buffer. */ | |
127 | ||
5260325f | 128 | void |
129 | buffer_consume_end(Buffer *buffer, unsigned int bytes) | |
8efc0c15 | 130 | { |
5260325f | 131 | if (bytes > buffer->end - buffer->offset) |
132 | fatal("buffer_get trying to get more bytes than in buffer"); | |
133 | buffer->end -= bytes; | |
134 | } | |
8efc0c15 | 135 | |
136 | /* Returns a pointer to the first used byte in the buffer. */ | |
137 | ||
5260325f | 138 | char * |
139 | buffer_ptr(Buffer *buffer) | |
8efc0c15 | 140 | { |
5260325f | 141 | return buffer->buf + buffer->offset; |
8efc0c15 | 142 | } |
143 | ||
144 | /* Dumps the contents of the buffer to stderr. */ | |
145 | ||
5260325f | 146 | void |
147 | buffer_dump(Buffer *buffer) | |
8efc0c15 | 148 | { |
5260325f | 149 | int i; |
150 | unsigned char *ucp = (unsigned char *) buffer->buf; | |
151 | ||
152 | for (i = buffer->offset; i < buffer->end; i++) | |
153 | fprintf(stderr, " %02x", ucp[i]); | |
154 | fprintf(stderr, "\n"); | |
8efc0c15 | 155 | } |