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 static struct line_buffer buf_ = LINE_BUFFER_INIT;
  12 static struct line_buffer *buf;
  13
  14 int buffer_init(const char *filename)
  15 {
  16         buf = &buf_;
  17
  18         buf->infile = filename ? fopen(filename, "r") : stdin;
  19         if (!buf->infile)
  20                 return -1;
  21         return 0;
  22 }
  23
  24 int buffer_deinit(void)
  25 {
  26         int err;
  27         if (buf->infile == stdin)
  28                 return ferror(buf->infile);
  29         err = ferror(buf->infile);
  30         err |= fclose(buf->infile);
  31         return err;
  32 }
  33
  34 /* Read a line without trailing newline. */
  35 char *buffer_read_line(void)
  36 {
  37         char *end;
  38         if (!fgets(buf->line_buffer, sizeof(buf->line_buffer), buf->infile))
  39                 /* Error or data exhausted. */
  40                 return NULL;
  41         end = buf->line_buffer + strlen(buf->line_buffer);
  42         if (end[-1] == '\n')
  43                 end[-1] = '\0';
  44         else if (feof(buf->infile))
  45                 ; /* No newline at end of file.  That's fine. */
  46         else
  47                 /*
  48                  * Line was too long.
  49                  * There is probably a saner way to deal with this,
  50                  * but for now let's return an error.
  51                  */
  52                 return NULL;
  53         return buf->line_buffer;
  54 }
  55
  56 char *buffer_read_string(uint32_t len)
  57 {
  58         strbuf_reset(&buf->blob_buffer);
  59         strbuf_fread(&buf->blob_buffer, len, buf->infile);
  60         return ferror(buf->infile) ? NULL : buf->blob_buffer.buf;
  61 }
  62
  63 void buffer_copy_bytes(uint32_t len)
  64 {
  65         char byte_buffer[COPY_BUFFER_LEN];
  66         uint32_t in;
  67         while (len > 0 && !feof(buf->infile) && !ferror(buf->infile)) {
  68                 in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
  69                 in = fread(byte_buffer, 1, in, buf->infile);
  70                 len -= in;
  71                 fwrite(byte_buffer, 1, in, stdout);
  72                 if (ferror(stdout)) {
  73                         buffer_skip_bytes(len);
  74                         return;
  75                 }
  76         }
  77 }
  78
  79 void buffer_skip_bytes(uint32_t len)
  80 {
  81         char byte_buffer[COPY_BUFFER_LEN];
  82         uint32_t in;
  83         while (len > 0 && !feof(buf->infile) && !ferror(buf->infile)) {
  84                 in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
  85                 in = fread(byte_buffer, 1, in, buf->infile);
  86                 len -= in;
  87         }
  88 }
  89
  90 void buffer_reset(void)
  91 {
  92         strbuf_release(&buf->blob_buffer);
  93 }