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_deinit(struct line_buffer *buf)
  21 {
  22         int err;
  23         if (buf->infile == stdin)
  24                 return ferror(buf->infile);
  25         err = ferror(buf->infile);
  26         err |= fclose(buf->infile);
  27         return err;
  28 }
  29
  30 /* Read a line without trailing newline. */
  31 char *buffer_read_line(struct line_buffer *buf)
  32 {
  33         char *end;
  34         if (!fgets(buf->line_buffer, sizeof(buf->line_buffer), buf->infile))
  35                 /* Error or data exhausted. */
  36                 return NULL;
  37         end = buf->line_buffer + strlen(buf->line_buffer);
  38         if (end[-1] == '\n')
  39                 end[-1] = '\0';
  40         else if (feof(buf->infile))
  41                 ; /* No newline at end of file.  That's fine. */
  42         else
  43                 /*
  44                  * Line was too long.
  45                  * There is probably a saner way to deal with this,
  46                  * but for now let's return an error.
  47                  */
  48                 return NULL;
  49         return buf->line_buffer;
  50 }
  51
  52 char *buffer_read_string(struct line_buffer *buf, uint32_t len)
  53 {
  54         strbuf_reset(&buf->blob_buffer);
  55         strbuf_fread(&buf->blob_buffer, len, buf->infile);
  56         return ferror(buf->infile) ? NULL : buf->blob_buffer.buf;
  57 }
  58
  59 void buffer_read_binary(struct line_buffer *buf,
  60                                 struct strbuf *sb, uint32_t size)
  61 {
  62         strbuf_fread(sb, size, buf->infile);
  63 }
  64
  65 void buffer_copy_bytes(struct line_buffer *buf, uint32_t len)
  66 {
  67         char byte_buffer[COPY_BUFFER_LEN];
  68         uint32_t in;
  69         while (len > 0 && !feof(buf->infile) && !ferror(buf->infile)) {
  70                 in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
  71                 in = fread(byte_buffer, 1, in, buf->infile);
  72                 len -= in;
  73                 fwrite(byte_buffer, 1, in, stdout);
  74                 if (ferror(stdout)) {
  75                         buffer_skip_bytes(buf, len);
  76                         return;
  77                 }
  78         }
  79 }
  80
  81 void buffer_skip_bytes(struct line_buffer *buf, uint32_t len)
  82 {
  83         char byte_buffer[COPY_BUFFER_LEN];
  84         uint32_t in;
  85         while (len > 0 && !feof(buf->infile) && !ferror(buf->infile)) {
  86                 in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
  87                 in = fread(byte_buffer, 1, in, buf->infile);
  88                 len -= in;
  89         }
  90 }
  91
  92 void buffer_reset(struct line_buffer *buf)
  93 {
  94         strbuf_release(&buf->blob_buffer);
  95 }