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 "obj_pool.h"
   9
  10 #define LINE_BUFFER_LEN 10000
  11 #define COPY_BUFFER_LEN 4096
  12
  13 /* Create memory pool for char sequence of known length */
  14 obj_pool_gen(blob, char, 4096)
  15
  16 static char line_buffer[LINE_BUFFER_LEN];
  17 static char byte_buffer[COPY_BUFFER_LEN];
  18 static FILE *infile;
  19
  20 int buffer_init(const char *filename)
  21 {
  22         infile = filename ? fopen(filename, "r") : stdin;
  23         if (!infile)
  24                 return -1;
  25         return 0;
  26 }
  27
  28 int buffer_deinit(void)
  29 {
  30         int err;
  31         if (infile == stdin)
  32                 return ferror(infile);
  33         err = ferror(infile);
  34         err |= fclose(infile);
  35         return err;
  36 }
  37
  38 /* Read a line without trailing newline. */
  39 char *buffer_read_line(void)
  40 {
  41         char *end;
  42         if (!fgets(line_buffer, sizeof(line_buffer), infile))
  43                 /* Error or data exhausted. */
  44                 return NULL;
  45         end = line_buffer + strlen(line_buffer);
  46         if (end[-1] == '\n')
  47                 end[-1] = '\0';
  48         else if (feof(infile))
  49                 ; /* No newline at end of file.  That's fine. */
  50         else
  51                 /*
  52                  * Line was too long.
  53                  * There is probably a saner way to deal with this,
  54                  * but for now let's return an error.
  55                  */
  56                 return NULL;
  57         return line_buffer;
  58 }
  59
  60 char *buffer_read_string(uint32_t len)
  61 {
  62         char *s;
  63         blob_free(blob_pool.size);
  64         s = blob_pointer(blob_alloc(len + 1));
  65         s[fread(s, 1, len, infile)] = '\0';
  66         return ferror(infile) ? NULL : s;
  67 }
  68
  69 void buffer_copy_bytes(uint32_t len)
  70 {
  71         uint32_t in;
  72         while (len > 0 && !feof(infile) && !ferror(infile)) {
  73                 in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
  74                 in = fread(byte_buffer, 1, in, infile);
  75                 len -= in;
  76                 fwrite(byte_buffer, 1, in, stdout);
  77                 if (ferror(stdout)) {
  78                         buffer_skip_bytes(len);
  79                         return;
  80                 }
  81         }
  82 }
  83
  84 void buffer_skip_bytes(uint32_t len)
  85 {
  86         uint32_t in;
  87         while (len > 0 && !feof(infile) && !ferror(infile)) {
  88                 in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
  89                 in = fread(byte_buffer, 1, in, infile);
  90                 len -= in;
  91         }
  92 }
  93
  94 void buffer_reset(void)
  95 {
  96         blob_reset();
  97 }