swh:1:snp:ff2a11cd2e44dd19ec3814028ef2ce6605664e63
Tip revision: 37ff3d2a65f4758d6fa038c13a8f2177cb57f41a authored by Eric Fischer on 03 January 2018, 20:49:24 UTC
Type cleanup: geometry operations are unsigned chars
Type cleanup: geometry operations are unsigned chars
Tip revision: 37ff3d2
memfile.cpp
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include "memfile.hpp"
#define INCREMENT 131072
#define INITIAL 256
struct memfile *memfile_open(int fd) {
if (ftruncate(fd, INITIAL) != 0) {
return NULL;
}
char *map = (char *) mmap(NULL, INITIAL, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (map == MAP_FAILED) {
return NULL;
}
struct memfile *mf = new memfile;
if (mf == NULL) {
munmap(map, INITIAL);
return NULL;
}
mf->fd = fd;
mf->map = map;
mf->len = INITIAL;
mf->off = 0;
mf->tree = 0;
return mf;
}
int memfile_close(struct memfile *file) {
if (munmap(file->map, file->len) != 0) {
return -1;
}
if (file->fd >= 0) {
if (close(file->fd) != 0) {
return -1;
}
}
delete file;
return 0;
}
ssize_t memfile_write(struct memfile *file, void *s, size_t len) {
if (file->off + len > file->len) {
if (munmap(file->map, file->len) != 0) {
return -1;
}
file->len += (len + INCREMENT + 1) / INCREMENT * INCREMENT;
if (ftruncate(file->fd, (off_t) file->len) != 0) {
return -1;
}
file->map = (char *) mmap(NULL, file->len, PROT_READ | PROT_WRITE, MAP_SHARED, file->fd, 0);
if (file->map == MAP_FAILED) {
return -1;
}
}
memcpy(file->map + file->off, s, len);
file->off += len;
return (ssize_t) len;
}