line_buffer.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4
   5 #include "line_buffer.h"
   6 #include "obj_pool.h"
   7
   8 #define LINE_BUFFER_LEN 10000
   9 #define COPY_BUFFER_LEN 4096
  10
  11 /* Create memory pool for char sequence of known length */
  12 obj_pool_gen(blob, char, 4096);
  13
  14 static char line_buffer[LINE_BUFFER_LEN];
  15 static char byte_buffer[COPY_BUFFER_LEN];
  16 static uint32_t line_buffer_len = 0;
  17 static uint32_t line_len = 0;
  18
  19 char *buffer_read_line(void)
  20 {
  21     char *end;
  22     uint32_t n_read;
  23
  24     if (line_len) {
  25         memmove(line_buffer, &line_buffer[line_len],
  26                 line_buffer_len - line_len);
  27         line_buffer_len -= line_len;
  28         line_len = 0;
  29     }
  30
  31     end = memchr(line_buffer, '\n', line_buffer_len);
  32     while (line_buffer_len < LINE_BUFFER_LEN - 1 &&
  33            !feof(stdin) && NULL == end) {
  34         n_read =
  35             fread(&line_buffer[line_buffer_len], 1,
  36                   LINE_BUFFER_LEN - 1 - line_buffer_len,
  37                   stdin);
  38         end = memchr(&line_buffer[line_buffer_len], '\n', n_read);
  39         line_buffer_len += n_read;
  40     }
  41
  42     if (ferror(stdin))
  43         return NULL;
  44
  45     if (end != NULL) {
  46         line_len = end - line_buffer;
  47         line_buffer[line_len++] = '\0';
  48     } else {
  49         line_len = line_buffer_len;
  50         line_buffer[line_buffer_len] = '\0';
  51     }
  52
  53     if (line_len == 0)
  54         return NULL;
  55
  56     return line_buffer;
  57 }
  58
  59 char *buffer_read_string(uint32_t len)
  60 {
  61     char *s;
  62     blob_free(blob_pool.size);
  63     s = blob_pointer(blob_alloc(len + 1));
  64     uint32_t offset = 0;
  65     if (line_buffer_len > line_len) {
  66         offset = line_buffer_len - line_len;
  67         if (offset > len)
  68             offset = len;
  69         memcpy(s, &line_buffer[line_len], offset);
  70         line_len += offset;
  71     }
  72     while (offset < len && !feof(stdin)) {
  73         offset += fread(&s[offset], 1, len - offset, stdin);
  74     }
  75     s[offset] = '\0';
  76     return s;
  77 }
  78
  79 void buffer_copy_bytes(uint32_t len)
  80 {
  81     uint32_t in, out;
  82     if (line_buffer_len > line_len) {
  83         in = line_buffer_len - line_len;
  84         if (in > len)
  85             in = len;
  86         out = 0;
  87         while (out < in && !ferror(stdout)) {
  88             out +=
  89                 fwrite(&line_buffer[line_len + out], 1, in - out, stdout);
  90         }
  91         len -= in;
  92         line_len += in;
  93     }
  94     while (len > 0 && !feof(stdin)) {
  95         in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
  96         in = fread(byte_buffer, 1, in, stdin);
  97         len -= in;
  98         out = 0;
  99         while (out < in && !ferror(stdout)) {
 100             out += fwrite(&byte_buffer[out], 1, in - out, stdout);
 101         }
 102     }
 103 }
 104
 105 void buffer_skip_bytes(uint32_t len)
 106 {
 107     uint32_t in;
 108     if (line_buffer_len > line_len) {
 109         in = line_buffer_len - line_len;
 110         if (in > len)
 111             in = len;
 112         line_len += in;
 113         len -= in;
 114     }
 115     while (len > 0 && !feof(stdin)) {
 116         in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
 117         in = fread(byte_buffer, 1, in, stdin);
 118         len -= in;
 119     }
 120 }
 121
 122 void buffer_reset(void)
 123 {
 124     blob_reset();
 125 }