(file-handler)+impl file for file handling

In particular I've implemented a standardised complete FILE * reader
without relying on fseek (which may not work for pipes).

2 files changed, 65 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 5f13bd7..deb3b80 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 CC=gcc
 CFLAGS=-Wall -Wextra -pedantic -ggdb -fsanitize=address
 LIBS=-lm -lraylib
-OBJECTS=main.o
+OBJECTS=file-handler.o main.o
 OUT=sandpile.out
 ARGS=
 
diff --git a/file-handler.c b/file-handler.c
new file mode 100644
index 0000000..765eec5
--- /dev/null
+++ b/file-handler.c
@@ -0,0 +1,64 @@
+/* file-handler.c
+ * Created: 2023-08-25
+ * Author: Aryadev Chavali
+ * Description: Implementations of writing and loading state from files
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include "./lib.h"
+
+#define CHUNK_SIZE 1024
+
+typedef struct Buffer
+{
+  char *data;
+  size_t used, available;
+} buffer_t;
+
+void buffer_init(buffer_t *buffer)
+{
+  *buffer =
+      (buffer_t){calloc(CHUNK_SIZE, sizeof(*buffer->data)), 0, CHUNK_SIZE};
+}
+
+void buffer_realloc(buffer_t *buffer, size_t new_size)
+{
+  buffer->data      = realloc(buffer->data, new_size);
+  buffer->available = new_size;
+}
+
+void buffer_tighten(buffer_t *buffer)
+{
+  buffer->data               = realloc(buffer->data, buffer->used + 1);
+  buffer->data[buffer->used] = '\0';
+  buffer->available          = buffer->used;
+}
+
+bool load_from_file(state_t *state, const char *filepath)
+{
+  memset(state->data, 0, state->dwidth * state->dwidth);
+  // Read file completely
+  FILE *fp = fopen(filepath, "r");
+  buffer_t buffer;
+  buffer_init(&buffer);
+  size_t bytes_read = 0;
+  while ((bytes_read =
+              fread(buffer.data, sizeof(*buffer.data), CHUNK_SIZE, fp)) != 0)
+  {
+    buffer.used += bytes_read;
+    buffer_realloc(&buffer, buffer.available + CHUNK_SIZE);
+  }
+  fclose(fp);
+  buffer_tighten(&buffer);
+
+  // Now parse it
+
+  free(buffer.data);
+
+  return true;
+}
+
+bool write_to_file(state_t *state, const char *filepath)
+{}