1 files changed, 72 insertions, 0 deletions
diff --git a/extract/include/extract_buffer_impl.h b/extract/include/extract_buffer_impl.h
new file mode 100644
index 00000000..25f533dd
--- /dev/null
+++ b/extract/include/extract_buffer_impl.h
@@ -0,0 +1,72 @@
+/* Implementation of inline functions.
+
+We expose some implementation details to allow extract_buffer_read() and
+extract_buffer_write() to be inline; specifically we allow the compiler to
+optimise the common case where reading/writing uses the cache only. */
+
+
+#include <string.h>
+
+typedef struct
+{
+    void*   cache;
+    size_t  numbytes;
+    size_t  pos;
+} extract_buffer_cache_t;
+
+
+int extract_buffer_read_internal(
+        extract_buffer_t*   buffer,
+        void*               data,
+        size_t              numbytes,
+        size_t*             o_actual
+        );
+/* Internal use only. */
+
+static inline int extract_buffer_read(
+        extract_buffer_t*   buffer,
+        void*               data,
+        size_t              numbytes,
+        size_t*             o_actual
+        )
+{
+    extract_buffer_cache_t* cache = (void*) buffer;
+    if (cache->numbytes - cache->pos < numbytes) {
+        /* Can't use just the cache. */
+        return extract_buffer_read_internal(buffer, data, numbytes, o_actual);
+    }
+    /* We can use just the cache. */
+    memcpy(data, (char*) cache->cache + cache->pos, numbytes);
+    cache->pos += numbytes;
+    if (o_actual) *o_actual = numbytes;
+    return 0;
+}
+
+
+int extract_buffer_write_internal(
+        extract_buffer_t*   buffer,
+        const void*         data,
+        size_t              numbytes,
+        size_t*             o_actual
+        );
+/* Internal use only. */
+
+static inline int extract_buffer_write(
+        extract_buffer_t*   buffer,
+        const void*         data,
+        size_t              numbytes,
+        size_t*             o_actual
+        )
+{
+    extract_buffer_cache_t* cache = (void*) buffer;
+    if (cache->numbytes - cache->pos < numbytes) {
+        /* Can't use just the cache. */
+        return extract_buffer_write_internal(buffer, data, numbytes, o_actual);
+    }
+    /* We can use just the cache. */
+    memcpy((char*) cache->cache + cache->pos, data, numbytes);
+    cache->pos += numbytes;
+    if (o_actual) *o_actual = numbytes;
+    return 0;
+}
+