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1 | /** @file\r | |
2 | Implementation of internal file buffer allocation functions.\r | |
3 | \r | |
4 | Copyright (c) 2010 - 2012, Intel Corporation. All rights reserved.<BR>\r | |
5 | This program and the accompanying materials are licensed and made available\r | |
6 | under the terms and conditions of the BSD License that accompanies this\r | |
7 | distribution. The full text of the license may be found at\r | |
8 | http://opensource.org/licenses/bsd-license.\r | |
9 | \r | |
10 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
11 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
12 | \r | |
13 | Copyright (c) 1990, 1993\r | |
14 | The Regents of the University of California. All rights reserved.\r | |
15 | \r | |
16 | This code is derived from software contributed to Berkeley by\r | |
17 | Chris Torek.\r | |
18 | \r | |
19 | Redistribution and use in source and binary forms, with or without\r | |
20 | modification, are permitted provided that the following conditions\r | |
21 | are met:\r | |
22 | - Redistributions of source code must retain the above copyright\r | |
23 | notice, this list of conditions and the following disclaimer.\r | |
24 | - Redistributions in binary form must reproduce the above copyright\r | |
25 | notice, this list of conditions and the following disclaimer in the\r | |
26 | documentation and/or other materials provided with the distribution.\r | |
27 | - Neither the name of the University nor the names of its contributors\r | |
28 | may be used to endorse or promote products derived from this software\r | |
29 | without specific prior written permission.\r | |
30 | \r | |
31 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"\r | |
32 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE\r | |
33 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE\r | |
34 | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE\r | |
35 | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR\r | |
36 | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF\r | |
37 | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS\r | |
38 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN\r | |
39 | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)\r | |
40 | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE\r | |
41 | POSSIBILITY OF SUCH DAMAGE.\r | |
42 | \r | |
43 | NetBSD: makebuf.c,v 1.14 2003/08/07 16:43:28 agc Exp\r | |
44 | makebuf.c 8.1 (Berkeley) 6/4/93\r | |
45 | **/\r | |
46 | #include <LibConfig.h>\r | |
47 | \r | |
48 | #include "namespace.h"\r | |
49 | \r | |
50 | #include <sys/types.h>\r | |
51 | #include <sys/stat.h>\r | |
52 | #include <assert.h>\r | |
53 | #include <stdio.h>\r | |
54 | #include <stdlib.h>\r | |
55 | #include <unistd.h>\r | |
56 | #include "reentrant.h"\r | |
57 | #include "local.h"\r | |
58 | #include <MainData.h>\r | |
59 | \r | |
60 | /*\r | |
61 | * Allocate a file buffer, or switch to unbuffered I/O.\r | |
62 | * Per the ANSI C standard, ALL tty devices default to line buffered.\r | |
63 | *\r | |
64 | * As a side effect, we set __SOPT or __SNPT (en/dis-able fseek\r | |
65 | * optimisation) right after the fstat() that finds the buffer size.\r | |
66 | */\r | |
67 | void\r | |
68 | __smakebuf(FILE *fp)\r | |
69 | {\r | |
70 | void *p;\r | |
71 | int flags;\r | |
72 | size_t size;\r | |
73 | int couldbetty;\r | |
74 | \r | |
75 | _DIAGASSERT(fp != NULL);\r | |
76 | \r | |
77 | if (fp != NULL) {\r | |
78 | if (fp->_flags & __SNBF) {\r | |
79 | fp->_bf._base = fp->_p = fp->_nbuf;\r | |
80 | fp->_bf._size = MB_LEN_MAX;\r | |
81 | return;\r | |
82 | }\r | |
83 | flags = __swhatbuf(fp, &size, &couldbetty);\r | |
84 | if ((p = malloc(size)) == NULL) {\r | |
85 | // malloc failed, act unbuffered.\r | |
86 | fp->_flags |= __SNBF;\r | |
87 | fp->_bf._base = fp->_p = fp->_nbuf;\r | |
88 | fp->_bf._size = 1;\r | |
89 | return;\r | |
90 | }\r | |
91 | gMD->cleanup = _cleanup;\r | |
92 | flags |= __SMBF;\r | |
93 | fp->_bf._base = fp->_p = p;\r | |
94 | fp->_bf._size = (int)size;\r | |
95 | if (couldbetty || isatty(fp->_file))\r | |
96 | flags |= __SLBF;\r | |
97 | fp->_flags |= flags;\r | |
98 | }\r | |
99 | }\r | |
100 | \r | |
101 | /*\r | |
102 | * Internal routine to determine `proper' buffering for a file.\r | |
103 | */\r | |
104 | int\r | |
105 | __swhatbuf(FILE *fp, size_t *bufsize, int *couldbetty)\r | |
106 | {\r | |
107 | struct stat st;\r | |
108 | \r | |
109 | _DIAGASSERT(fp != NULL);\r | |
110 | _DIAGASSERT(bufsize != NULL);\r | |
111 | _DIAGASSERT(couldbetty != NULL);\r | |
112 | if(fp == NULL) {\r | |
113 | return (__SNPT);\r | |
114 | }\r | |
115 | \r | |
116 | if (fp->_file < 0 || fstat(fp->_file, &st) < 0) {\r | |
117 | *couldbetty = 0;\r | |
118 | *bufsize = BUFSIZ;\r | |
119 | return (__SNPT);\r | |
120 | }\r | |
121 | \r | |
122 | /* could be a tty iff it is a character device */\r | |
123 | *couldbetty = S_ISCHR(st.st_mode);\r | |
124 | if (st.st_blksize == 0) {\r | |
125 | *bufsize = BUFSIZ;\r | |
126 | return (__SNPT);\r | |
127 | }\r | |
128 | \r | |
129 | /*\r | |
130 | * Optimise fseek() only if it is a regular file. (The test for\r | |
131 | * __sseek is mainly paranoia.) It is safe to set _blksize\r | |
132 | * unconditionally; it will only be used if __SOPT is also set.\r | |
133 | */\r | |
134 | *bufsize = st.st_blksize;\r | |
135 | fp->_blksize = st.st_blksize;\r | |
136 | return ((st.st_mode & S_IFMT) == S_IFREG && fp->_seek == __sseek ?\r | |
137 | __SOPT : __SNPT);\r | |
138 | }\r |