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Commit | Line | Data |
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ef416fc2 | 1 | /* |
f2d18633 | 2 | * "$Id$" |
ef416fc2 | 3 | * |
7e86f2f6 | 4 | * Backchannel functions for CUPS. |
ef416fc2 | 5 | * |
7e86f2f6 MS |
6 | * Copyright 2007-2014 by Apple Inc. |
7 | * Copyright 1997-2007 by Easy Software Products. | |
ef416fc2 | 8 | * |
7e86f2f6 MS |
9 | * These coded instructions, statements, and computer programs are the |
10 | * property of Apple Inc. and are protected by Federal copyright | |
11 | * law. Distribution and use rights are outlined in the file "LICENSE.txt" | |
12 | * which should have been included with this file. If this file is | |
13 | * file is missing or damaged, see the license at "http://www.cups.org/". | |
ef416fc2 | 14 | * |
7e86f2f6 | 15 | * This file is subject to the Apple OS-Developed Software exception. |
ef416fc2 | 16 | */ |
17 | ||
18 | /* | |
19 | * Include necessary headers... | |
20 | */ | |
21 | ||
22 | #include "cups.h" | |
23 | #include <errno.h> | |
24 | #ifdef WIN32 | |
25 | # include <io.h> | |
26 | # include <fcntl.h> | |
27 | #else | |
28 | # include <sys/time.h> | |
29 | #endif /* WIN32 */ | |
30 | ||
31 | ||
32 | /* | |
33 | * Local functions... | |
34 | */ | |
35 | ||
36 | static void cups_setup(fd_set *set, struct timeval *tval, | |
37 | double timeout); | |
38 | ||
39 | ||
40 | /* | |
41 | * 'cupsBackChannelRead()' - Read data from the backchannel. | |
42 | * | |
79e1d494 MS |
43 | * Reads up to "bytes" bytes from the backchannel/backend. The "timeout" |
44 | * parameter controls how many seconds to wait for the data - use 0.0 to | |
45 | * return immediately if there is no data, -1.0 to wait for data indefinitely. | |
ef416fc2 | 46 | * |
f3c17241 | 47 | * @since CUPS 1.2/OS X 10.5@ |
ef416fc2 | 48 | */ |
49 | ||
ecdc0628 | 50 | ssize_t /* O - Bytes read or -1 on error */ |
79e1d494 | 51 | cupsBackChannelRead(char *buffer, /* I - Buffer to read into */ |
ecdc0628 | 52 | size_t bytes, /* I - Bytes to read */ |
79e1d494 | 53 | double timeout) /* I - Timeout in seconds, typically 0.0 to poll */ |
ef416fc2 | 54 | { |
55 | fd_set input; /* Input set */ | |
56 | struct timeval tval; /* Timeout value */ | |
57 | int status; /* Select status */ | |
58 | ||
59 | ||
60 | /* | |
61 | * Wait for input ready. | |
62 | */ | |
63 | ||
64 | do | |
65 | { | |
66 | cups_setup(&input, &tval, timeout); | |
67 | ||
68 | if (timeout < 0.0) | |
69 | status = select(4, &input, NULL, NULL, NULL); | |
70 | else | |
71 | status = select(4, &input, NULL, NULL, &tval); | |
72 | } | |
e07d4801 | 73 | while (status < 0 && errno != EINTR && errno != EAGAIN); |
ef416fc2 | 74 | |
75 | if (status < 0) | |
76 | return (-1); /* Timeout! */ | |
77 | ||
78 | /* | |
79 | * Read bytes from the pipe... | |
80 | */ | |
81 | ||
b86bc4cf | 82 | #ifdef WIN32 |
536bc2c6 | 83 | return ((ssize_t)_read(3, buffer, (unsigned)bytes)); |
b86bc4cf | 84 | #else |
ef416fc2 | 85 | return (read(3, buffer, bytes)); |
b86bc4cf | 86 | #endif /* WIN32 */ |
ef416fc2 | 87 | } |
88 | ||
89 | ||
90 | /* | |
91 | * 'cupsBackChannelWrite()' - Write data to the backchannel. | |
92 | * | |
79e1d494 | 93 | * Writes "bytes" bytes to the backchannel/filter. The "timeout" parameter |
ef416fc2 | 94 | * controls how many seconds to wait for the data to be written - use |
95 | * 0.0 to return immediately if the data cannot be written, -1.0 to wait | |
96 | * indefinitely. | |
97 | * | |
f3c17241 | 98 | * @since CUPS 1.2/OS X 10.5@ |
ef416fc2 | 99 | */ |
100 | ||
ecdc0628 | 101 | ssize_t /* O - Bytes written or -1 on error */ |
bd7854cb | 102 | cupsBackChannelWrite( |
ef416fc2 | 103 | const char *buffer, /* I - Buffer to write */ |
ecdc0628 | 104 | size_t bytes, /* I - Bytes to write */ |
79e1d494 | 105 | double timeout) /* I - Timeout in seconds, typically 1.0 */ |
ef416fc2 | 106 | { |
107 | fd_set output; /* Output set */ | |
108 | struct timeval tval; /* Timeout value */ | |
109 | int status; /* Select status */ | |
ecdc0628 | 110 | ssize_t count; /* Current bytes */ |
111 | size_t total; /* Total bytes */ | |
ef416fc2 | 112 | |
113 | ||
114 | /* | |
115 | * Write all bytes... | |
116 | */ | |
117 | ||
118 | total = 0; | |
119 | ||
120 | while (total < bytes) | |
121 | { | |
122 | /* | |
123 | * Wait for write-ready... | |
124 | */ | |
125 | ||
126 | do | |
127 | { | |
128 | cups_setup(&output, &tval, timeout); | |
129 | ||
130 | if (timeout < 0.0) | |
131 | status = select(4, NULL, &output, NULL, NULL); | |
132 | else | |
133 | status = select(4, NULL, &output, NULL, &tval); | |
134 | } | |
e07d4801 | 135 | while (status < 0 && errno != EINTR && errno != EAGAIN); |
ef416fc2 | 136 | |
e07d4801 | 137 | if (status <= 0) |
ef416fc2 | 138 | return (-1); /* Timeout! */ |
139 | ||
140 | /* | |
141 | * Write bytes to the pipe... | |
142 | */ | |
143 | ||
b86bc4cf | 144 | #ifdef WIN32 |
536bc2c6 | 145 | count = (ssize_t)_write(3, buffer, (unsigned)(bytes - total)); |
b86bc4cf | 146 | #else |
ef416fc2 | 147 | count = write(3, buffer, bytes - total); |
b86bc4cf | 148 | #endif /* WIN32 */ |
ef416fc2 | 149 | |
150 | if (count < 0) | |
151 | { | |
152 | /* | |
153 | * Write error - abort on fatal errors... | |
154 | */ | |
155 | ||
e07d4801 | 156 | if (errno != EINTR && errno != EAGAIN) |
ef416fc2 | 157 | return (-1); |
158 | } | |
159 | else | |
160 | { | |
161 | /* | |
162 | * Write succeeded, update buffer pointer and total count... | |
163 | */ | |
164 | ||
165 | buffer += count; | |
7e86f2f6 | 166 | total += (size_t)count; |
ef416fc2 | 167 | } |
168 | } | |
169 | ||
b86bc4cf | 170 | return ((ssize_t)bytes); |
ef416fc2 | 171 | } |
172 | ||
173 | ||
174 | /* | |
f3c17241 | 175 | * 'cups_setup()' - Setup select() |
ef416fc2 | 176 | */ |
177 | ||
178 | static void | |
179 | cups_setup(fd_set *set, /* I - Set for select() */ | |
180 | struct timeval *tval, /* I - Timer value */ | |
181 | double timeout) /* I - Timeout in seconds */ | |
182 | { | |
183 | tval->tv_sec = (int)timeout; | |
184 | tval->tv_usec = (int)(1000000.0 * (timeout - tval->tv_sec)); | |
185 | ||
186 | FD_ZERO(set); | |
187 | FD_SET(3, set); | |
188 | } | |
189 | ||
190 | ||
191 | /* | |
f2d18633 | 192 | * End of "$Id$". |
ef416fc2 | 193 | */ |