New filesystem API

2 files changed, 58 insertions, 27 deletions

diff --git a/filesystem/include/filesystem.h b/filesystem/include/filesystem.h
index 1c354b7..bc7f953 100644
--- a/filesystem/include/filesystem.h
+++ b/filesystem/include/filesystem.h
@@ -6,8 +6,26 @@
 #include <stddef.h>
 #include <stdio.h>
 
+#define WITH_FILE(FILEPATH, BODY)       \
+  {                                     \
+    assert(FILEPATH);                   \
+    FILE* file = fopen(FILEPATH, "rb"); \
+    if (file) {                         \
+      BODY;                             \
+      fclose(file);                     \
+    }                                   \
+  }
+
+/// Get the file's size.
+size_t get_file_size(const char* filename);
+
 /// Get the file's size.
-size_t get_file_size(FILE* file);
+size_t get_file_size_f(FILE* file);
 
 /// Read the entire contents of the file into memory.
 void* read_file(const char* filepath);
+
+/// Read the entire contents of the file into memory.
+///
+/// The given buffer must be large enough to hold the file's contents.
+bool read_file_f(FILE*, void* buffer);
diff --git a/filesystem/src/filesystem.c b/filesystem/src/filesystem.c
index b0c207a..b30c072 100644
--- a/filesystem/src/filesystem.c
+++ b/filesystem/src/filesystem.c
@@ -5,21 +5,27 @@
 #include <stdlib.h>
 #include <string.h>
 
-size_t get_file_size(FILE* file) {
+size_t get_file_size(const char* filename) {
+  size_t size = 0;
+  WITH_FILE(filename, size = get_file_size_f(file));
+  return size;
+}
+
+size_t get_file_size_f(FILE* file) {
   assert(file);
   const long int starting_pos = ftell(file);
   if (starting_pos == -1) {
-    return (size_t)-1;
+    return 0;
   }
   if (fseek(file, 0, SEEK_END) != 0) {
-    return (size_t)-1;
+    return 0;
   }
   const size_t file_size = ftell(file);
   if (file_size == (size_t)-1) {
-    return (size_t)-1;
+    return 0;
   }
   if (fseek(file, starting_pos, SEEK_SET) != 0) {
-    return (size_t)-1;
+    return 0;
   }
   return file_size;
 }
@@ -27,31 +33,38 @@ size_t get_file_size(FILE* file) {
 void* read_file(const char* filepath) {
   assert(filepath);
 
-  void* data = nullptr;
+  void* data    = nullptr;
+  bool  success = false;
 
-  FILE* file = fopen(filepath, "rb");
-  if (!file) {
-    return nullptr;
-  }
-  const size_t file_size = get_file_size(file);
-  if (file_size == (size_t)-1) {
-    goto cleanup;
-  }
+  WITH_FILE(filepath, {
+    const size_t file_size = get_file_size_f(file);
+    if (file_size > 0) {
+      data = calloc(1, file_size);
+      if (data != nullptr) {
+        if (fread(data, 1, file_size, file) == file_size) {
+          success = true;
+        }
+      }
+    }
+  });
 
-  data = calloc(1, file_size);
-  if (!data) {
-    goto cleanup;
-  }
-  if (fread(data, 1, file_size, file) != file_size) {
-    goto cleanup;
+  if (!success) {
+    free(data);
+    data = nullptr;
   }
-
   return data;
+}
 
-cleanup:
-  fclose(file);
-  if (data) {
-    free(data);
+bool read_file_f(FILE* file, void* buffer) {
+  assert(file);
+  assert(buffer);
+
+  bool         success   = false;
+  const size_t file_size = get_file_size_f(file);
+  if (file_size > 0) {
+    if (fread(buffer, 1, file_size, file) == file_size) {
+      success = true;
+    }
   }
-  return nullptr;
+  return success;
 }