meta: add compress module for (de)compressing data

compress/function.c

@@ -0,0 +1,48 @@
+#include "function.h"
+
+#include <blue/compress/compressor.h>
+#include <blue/compress/function.h>
+
+#ifdef B_COMPRESSOR_SUPPORTED_ZSTD
+extern const struct b_compression_function z__b_compression_function_zstd;
+#endif
+
+static const struct b_compression_function *compressor_functions[] = {
+#ifdef B_COMPRESSOR_SUPPORTED_ZSTD
+	[B_COMPRESSOR_FUNCTION_ZSTD] = &z__b_compression_function_zstd,
+#endif
+};
+static const size_t nr_compressor_functions
+	= sizeof compressor_functions / sizeof compressor_functions[0];
+
+const struct b_compression_function *b_compression_function_get_by_id(
+	enum b_compression_function_id id)
+{
+	if (id < 0 || id >= nr_compressor_functions) {
+		return NULL;
+	}
+
+	return compressor_functions[id];
+}
+
+enum b_status b_compression_function_get_buffer_size(
+	const struct b_compression_function *func, enum b_compressor_mode mode,
+	size_t *inbuf_size, size_t *outbuf_size)
+{
+	if (!func->f_buffer_size) {
+		return B_ERR_NOT_SUPPORTED;
+	}
+
+	size_t in = 0, out = 0;
+	enum b_status status = func->f_buffer_size(mode, &in, &out);
+
+	if (inbuf_size) {
+		*inbuf_size = in;
+	}
+
+	if (outbuf_size) {
+		*outbuf_size = out;
+	}
+
+	return status;
+}