1 files changed, 14 insertions, 10 deletions

diff --git a/lisiblepng-bin/src/main.c b/lisiblepng-bin/src/main.c
index 47e1722..116125a 100644
--- a/lisiblepng-bin/src/main.c
+++ b/lisiblepng-bin/src/main.c
@@ -1,8 +1,12 @@
 #include <errno.h>
+#include <fcntl.h>
 #include <lisiblepng.h>
 #include <lisiblestd/log.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
 
 #define LOG0(msg) fprintf(stderr, msg "\n")
 #define LOGN(fmt, ...) fprintf(stderr, fmt "\n", __VA_ARGS__)
@@ -15,19 +19,19 @@ int main(int argc, char **argv) {
   }
 
   const char *png_filepath = argv[1];
-  FILE *png_file = fopen(png_filepath, "r");
-  fseek(png_file, 0, SEEK_END);
-  long file_size = ftell(png_file);
-  LOGN("File size: %ld bytes", file_size);
-  fseek(png_file, 0, SEEK_SET);
+  int fd = open(png_filepath, O_RDONLY);
+  struct stat st;
+  fstat(fd, &st);
+  u8 *png_file_data = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
+  LOGN("File size: %ld bytes", st.st_size);
 
-  if (!png_file) {
+  if (!png_file_data) {
     const char *error_message = strerror(errno);
-    LOGN("Couldn't open PNG file: %s", error_message);
+    LOGN("Couldn't map PNG file: %s", error_message);
     return 1;
   }
 
-  LisPng *png = LisPng_decode(png_file);
+  LisPng *png = LisPng_decode(png_file_data, st.st_size);
   if (!png) {
     LOG0("Couldn't decode PNG");
     return 1;
@@ -36,9 +40,9 @@ int main(int argc, char **argv) {
   LisPng_dump_ppm(png);
   LisPng_destroy(png);
 
-  if (fclose(png_file) != 0) {
+  if (munmap(png_file_data, st.st_size) != 0) {
     const char *error_message = strerror(errno);
-    LOGN("Couldn't close PNG file: %s", error_message);
+    LOGN("Couldn't unmap PNG file: %s", error_message);
     return 1;
   }