compress und uncompress Funktionen

1 files changed, 71 insertions, 22 deletions

diff --git a/src/simple.c b/src/simple.c
index 5209841..36f7e48 100644
--- a/src/simple.c
+++ b/src/simple.c
@@ -15,21 +15,85 @@ usage(void)
         exit(EXIT_FAILURE);
 }
 
+unsigned long
+get_filesize(FILE *file)
+{
+        (void) fseek(file, 0, SEEK_END);
+        unsigned long size = ftell(file);
+        (void) fseek(file, 0, SEEK_SET);
+        return size;
+}
+
+void
+do_compress(FILE *in_file, FILE *out_file, int compress_level)
+{
+        const unsigned long in_size = get_filesize(in_file);
+
+        (void) fwrite(&in_size, sizeof in_size, 1, out_file);
+
+        unsigned char *in_data = malloc(in_size);
+        (void) fread(in_data, 1, in_size, in_file);
+
+        unsigned long  out_size = compressBound(in_size);
+        unsigned char *out_data = malloc(out_size);
+
+        const int error = compress2(out_data, &out_size, in_data, in_size, compress_level);
+
+        if ( !error ) {
+                (void) fwrite(out_data, 1, out_size, out_file);
+        }
+        else {
+                printf("Error: %d\n", error);
+        }
+
+        free(out_data);
+        free(in_data);
+}
+
+void
+do_uncompress(FILE *in_file, FILE *out_file)
+{
+        const unsigned long in_size = get_filesize(in_file);
+
+        unsigned char *in_data = malloc(in_size);
+        (void) fread(in_data, 1, in_size, in_file);
+
+        unsigned long  out_size = *(unsigned long *) in_data;
+        unsigned char *out_data = malloc(out_size);
+
+        unsigned long tmp = in_size - sizeof(unsigned long);
+
+        const int error = uncompress2(out_data,
+                                      &out_size,
+                                      in_data + sizeof(unsigned long),
+                                      &tmp);
+
+        if ( !error ) {
+                (void) fwrite(out_data, 1, out_size, out_file);
+        }
+        else {
+                printf("Error: %d\n", error);
+        }
+
+        free(out_data);
+        free(in_data);
+}
+
 int
 main(int argc, char *argv[])
 {
-        // int compress = 1;
-        int level = 5;
+        int decompress     = 0;
+        int compress_level = 5;
 
         int opt = 0;
         while ( (opt = getopt(argc, argv, "dl")) != -1 ) {
                 switch ( opt ) {
                 case 'd':
-                        // compress = 0; // decompress
+                        decompress = 1;
                         break;
 
                 case 'l':
-                        level = 9;
+                        compress_level = 9;
                         break;
 
                 case '?':
@@ -48,28 +112,13 @@ main(int argc, char *argv[])
         FILE *in_file  = fopen(argv[0], "rb");
         FILE *out_file = fopen(argv[1], "wb");
 
-        (void) fseek(in_file, 0, SEEK_END);
-        unsigned long insize = ftell(in_file); // max 2GB...
-        (void) fseek(in_file, 0, SEEK_SET);
-
-        unsigned char *indata = malloc(insize);
-        (void) fread(indata, 1, insize, in_file);
-
-        unsigned long  outsize = compressBound(insize);
-        unsigned char *outdata = malloc(outsize);
-
-        int res = compress2(outdata, &outsize, indata, insize, level);
-
-        if ( res == Z_OK ) {
-                (void) fwrite(outdata, 1, outsize, out_file);
+        if ( !decompress ) {
+                do_compress(in_file, out_file, compress_level);
         }
         else {
-                printf("Error: %d\n", res);
+                do_uncompress(in_file, out_file);
         }
 
-        free(outdata);
-        free(indata);
-
         (void) fclose(out_file);
         (void) fclose(in_file);