Merge branch 'rs/nth-switch-code-simplification'
[git/git.git] / vcs-svn / line_buffer.c
1 /*
2 * Licensed under a two-clause BSD-style license.
3 * See LICENSE for details.
4 */
5
6 #include "git-compat-util.h"
7 #include "line_buffer.h"
8 #include "strbuf.h"
9
10 #define COPY_BUFFER_LEN 4096
11
12 int buffer_init(struct line_buffer *buf, const char *filename)
13 {
14 buf->infile = filename ? fopen(filename, "r") : stdin;
15 if (!buf->infile)
16 return -1;
17 return 0;
18 }
19
20 int buffer_fdinit(struct line_buffer *buf, int fd)
21 {
22 buf->infile = fdopen(fd, "r");
23 if (!buf->infile)
24 return -1;
25 return 0;
26 }
27
28 int buffer_tmpfile_init(struct line_buffer *buf)
29 {
30 buf->infile = tmpfile();
31 if (!buf->infile)
32 return -1;
33 return 0;
34 }
35
36 int buffer_deinit(struct line_buffer *buf)
37 {
38 int err;
39 if (buf->infile == stdin)
40 return ferror(buf->infile);
41 err = ferror(buf->infile);
42 err |= fclose(buf->infile);
43 return err;
44 }
45
46 FILE *buffer_tmpfile_rewind(struct line_buffer *buf)
47 {
48 rewind(buf->infile);
49 return buf->infile;
50 }
51
52 long buffer_tmpfile_prepare_to_read(struct line_buffer *buf)
53 {
54 long pos = ftell(buf->infile);
55 if (pos < 0)
56 return error_errno("ftell error");
57 if (fseek(buf->infile, 0, SEEK_SET))
58 return error_errno("seek error");
59 return pos;
60 }
61
62 int buffer_ferror(struct line_buffer *buf)
63 {
64 return ferror(buf->infile);
65 }
66
67 int buffer_read_char(struct line_buffer *buf)
68 {
69 return fgetc(buf->infile);
70 }
71
72 /* Read a line without trailing newline. */
73 char *buffer_read_line(struct line_buffer *buf)
74 {
75 char *end;
76 if (!fgets(buf->line_buffer, sizeof(buf->line_buffer), buf->infile))
77 /* Error or data exhausted. */
78 return NULL;
79 end = buf->line_buffer + strlen(buf->line_buffer);
80 if (end[-1] == '\n')
81 end[-1] = '\0';
82 else if (feof(buf->infile))
83 ; /* No newline at end of file. That's fine. */
84 else
85 /*
86 * Line was too long.
87 * There is probably a saner way to deal with this,
88 * but for now let's return an error.
89 */
90 return NULL;
91 return buf->line_buffer;
92 }
93
94 size_t buffer_read_binary(struct line_buffer *buf,
95 struct strbuf *sb, size_t size)
96 {
97 return strbuf_fread(sb, size, buf->infile);
98 }
99
100 off_t buffer_copy_bytes(struct line_buffer *buf, off_t nbytes)
101 {
102 char byte_buffer[COPY_BUFFER_LEN];
103 off_t done = 0;
104 while (done < nbytes && !feof(buf->infile) && !ferror(buf->infile)) {
105 off_t len = nbytes - done;
106 size_t in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
107 in = fread(byte_buffer, 1, in, buf->infile);
108 done += in;
109 fwrite(byte_buffer, 1, in, stdout);
110 if (ferror(stdout))
111 return done + buffer_skip_bytes(buf, nbytes - done);
112 }
113 return done;
114 }
115
116 off_t buffer_skip_bytes(struct line_buffer *buf, off_t nbytes)
117 {
118 char byte_buffer[COPY_BUFFER_LEN];
119 off_t done = 0;
120 while (done < nbytes && !feof(buf->infile) && !ferror(buf->infile)) {
121 off_t len = nbytes - done;
122 size_t in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
123 done += fread(byte_buffer, 1, in, buf->infile);
124 }
125 return done;
126 }