Split file handling to a separate library with some added safety checks

src/utils/io.c

@@ -0,0 +1,55 @@
+
+#include <string.h>
+
+#include "utils/io.h"
+#include "utils/log.h"
+#include "utils/miscmath.h"
+
+#define READ_BLOCK_SIZE 32
+
+FILE *file_open(const char *file_name, const char *mode) {
+    FILE *handle = fopen(file_name, mode);
+    if(handle == NULL) {
+        PERROR("Unable to open file: %s: %d", file_name, strerror(errno));
+        abort();
+    }
+    return handle;
+}
+
+void file_seek(FILE *handle, long offset, int origin) {
+    if(fseek(handle, offset, origin)) {
+        PERROR("Unable to fseek to %d %d: %s", origin, offset, strerror(errno));
+        abort();
+    }
+}
+
+long file_size(FILE *handle) {
+    long pos, file_size;
+    pos = ftell(handle);
+    file_seek(handle, 0, SEEK_END);
+    file_size = ftell(handle);
+    file_seek(handle, pos, SEEK_SET);
+    return file_size;
+}
+
+void file_read(FILE *handle, char *buffer, long size) {
+    size_t ptr = 0;
+    size_t read_size;
+    while(1) {
+        if(feof(handle)) {
+            break;
+        }
+        if(ferror(handle)) {
+            PERROR("Error while reading file: %s", strerror(errno));
+            abort();
+        }
+        read_size = min2(size - ptr, READ_BLOCK_SIZE);
+        if(read_size <= 0)
+            break;
+        ptr += fread(buffer + ptr, 1, read_size, handle);
+    }
+}
+
+void file_close(FILE *handle) {
+    fclose(handle);
+}

src/utils/io.h

@@ -0,0 +1,12 @@
+#ifndef UTILS_IO_H
+#define UTILS_IO_H
+
+#include <stdio.h>
+
+FILE *file_open(const char *file_name, const char *mode);
+void file_seek(FILE *handle, long offset, int origin);
+long file_size(FILE *handle);
+void file_read(FILE *handle, char *buffer, long size);
+void file_close(FILE *handle);
+
+#endif // UTILS_IO_H

src/utils/str.c

@@ -1,5 +1,6 @@
 #include "utils/str.h"
 #include "utils/allocator.h"
+#include "utils/io.h"
 #include "utils/log.h"
 
 #include <assert.h>
@@ -8,6 +9,8 @@
 #include <stdlib.h>
 #include <string.h>
 
+#define READ_BLOCK_SIZE (1024)
+
 #define STR_ALLOC(string, size)                                                                                        \
     do {                                                                                                               \
         string->len = (size);                                                                                          \
@@ -42,35 +45,13 @@ void str_from_buf(str *dst, const char *buf, size_t len) {
     STR_ZERO(dst);
 }
 
-#define READ_BLOCK_SIZE 4096
-
 void str_from_file(str *dst, const char *file_name) {
-    FILE *handle = fopen(file_name, "rb");
-    if(handle == NULL) {
-        PERROR("Unable to read file: %s", file_name);
-        abort();
-    }
-
-    fseek(handle, 0, SEEK_END);
-    long file_size = ftell(handle);
-    fseek(handle, 0, SEEK_SET);
-
-    STR_ALLOC(dst, file_size);
-    size_t got;
-    char *ptr = dst->data;
-    while(1) {
-        if(feof(handle))
-            break;
-        if(ferror(handle))
-            break;
-        got = fread(ptr, 1, READ_BLOCK_SIZE, handle);
-        if(got != READ_BLOCK_SIZE)
-            break;
-        ptr += got;
-    }
+    FILE *handle = file_open(file_name, "rb");
+    long size = file_size(handle);
+    STR_ALLOC(dst, size + 1);
+    file_read(handle, dst->data, size);
+    file_close(handle);
     STR_ZERO(dst);
-
-    fclose(handle);
 }
 
 void str_from_format(str *dst, const char *format, ...) {