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("ftell error: %s", strerror(errno));
  57         if (fseek(buf->infile, 0, SEEK_SET))
  58                 return error("seek error: %s", strerror(errno));
  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 }