Files
langlanglang/src/file_stream.c

112 lines
2.0 KiB
C

#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>
#include "error.h"
#include "file_stream.h"
Mfile* mfile_open(Error* err, char* filename)
{
Mfile* s = malloc(sizeof *s);
if (!s) {
error_push(err, "failed to allocate file stream struct: %s", strerror(errno));
goto malloc_fail;
}
s->fd = open(filename, O_RDONLY);
if (s->fd == -1) {
error_push(err, "failed to open file %s: %s", filename, strerror(errno));
goto open_fail;
}
struct stat sb;
int ok = fstat(s->fd, &sb);
if (ok == -1) {
error_push(err, "failed to stat file %s: %s", filename, strerror(errno));
goto stat_fail;
}
s->size = sb.st_size;
s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, s->fd, 0);
if (s->data == MAP_FAILED) {
error_push(err, "failed to mmap file: %s", strerror(errno));
goto mmap_fail;
}
return s;
mmap_fail:
stat_fail:
close(s->fd);
open_fail:
free(s);
malloc_fail:
return NULL;
}
void mfile_close(Error* err, Mfile* s)
{
int ok;
ok = munmap(s->data, s->size);
if (ok == -1) {
error_push(err, "failed to munmap file: %s", strerror(errno));
}
close(s->fd);
if (ok == -1) {
error_push(err, "failed to close file: %s", strerror(errno));
}
free(s);
}
inline size_t mfile_inc_pos(Mfile* m)
{
return m->pos++;
}
inline size_t mfile_decr_pos(Mfile* m)
{
return m->pos--;
}
inline int mfile_get(Mfile* m)
{
if (m->pos >= m->size) {
return EOF;
}
return m->data[mfile_inc_pos(m)];
}
inline bool mfile_eof(Mfile* m)
{
return m->pos >= m->size;
}
inline char* mfile_cur(Mfile* m)
{
static char eof = EOF;
if (m->pos >= m->size) {
return &eof;
}
return m->data + m->pos;
}
inline int mfile_curchar(Mfile* m)
{
return *(mfile_cur(m));
}
void mfile_skip(Mfile* m, int (*f)(int))
{
while (f(mfile_curchar(m)))
mfile_inc_pos(m);
}