Fichiers audio, journal, annales

cours/audio/buffer.c

@@ -0,0 +1,61 @@
+#include "buffer.h"
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define max(a, b) ((a) <= (b) ? (a) : (b))
+
+void *malloc_checked(size_t size) {
+  void *result = malloc(size);
+  if (!result) {
+    perror("malloc()");
+    exit(EXIT_FAILURE);
+  }
+  return result;
+}
+
+char *strdup_checked(const char *s) {
+  char *result = strdup(s);
+  if (!result) {
+    perror("strdup()");
+    exit(EXIT_FAILURE);
+  }
+  return result;
+}
+
+buffer_t *buffer_alloc(size_t initial_size) {
+  buffer_t *buff = malloc_checked(sizeof *buff);
+  buff->data = malloc_checked(initial_size * sizeof *buff->data);
+  buff->size = initial_size;
+  buff->occupancy = 0;
+  return buff;
+}
+
+void buffer_free(buffer_t *buffer) {
+  assert (buffer);
+
+  free(buffer->data);
+  free(buffer);
+}
+
+void buffer_resize(buffer_t *buff, size_t new_size) {
+  assert (buff);
+  assert (new_size >= buff->size);
+
+  unsigned char *new_data = malloc_checked(new_size);
+  memcpy(new_data, buff->data, buff->occupancy);
+  free(buff->data);
+  buff->data = new_data;
+  buff->size = new_size;
+}
+
+void buffer_write(buffer_t *buff, void *data, size_t data_size) {
+  assert (buff);
+  if (buff->occupancy + data_size > buff->size)
+    buffer_resize(buff, max(buff->size + data_size, 2 * buff->size));
+  memcpy(buff->data + buff->occupancy, data, data_size);
+  buff->occupancy += data_size;
+}