From 6e7b8f94bf7fdc087cd1eed604eabed6070dffad Mon Sep 17 00:00:00 2001
From: Jon Bergli Heier <snakebite@jvnv.net>
Date: Wed, 2 Mar 2011 19:22:33 +0100
Subject: Implemented simple caching for transcoded audio data.

---
 cache.cpp | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 cache.cpp

(limited to 'cache.cpp')

diff --git a/cache.cpp b/cache.cpp
new file mode 100644
index 0000000..92e0cfa
--- /dev/null
+++ b/cache.cpp
@@ -0,0 +1,47 @@
+#include "cache.h"
+#include "config.h"
+
+#include <boost/format.hpp>
+#include <boost/filesystem/fstream.hpp>
+#include <openssl/sha.h>
+
+#include <iostream>
+#include <stdexcept>
+
+EncodedCache::EncodedCache(fs::path path, Decoder::p decoder, Encoder::p encoder) {
+	this->decoder = decoder;
+	this->encoder = encoder;
+
+	// TODO: Differentiate between encoders?
+	SHA_CTX context;
+	unsigned char md[SHA_DIGEST_LENGTH];
+	SHA_Init(&context);
+	SHA_Update(&context, (unsigned char*)path.string().c_str(), path.string().length());
+	SHA_Final(md, &context);
+	for(int i = 0; i < SHA_DIGEST_LENGTH; i++) {
+		hash = hash + (boost::format("%02x") % (int)md[i]).str();
+	}
+}
+
+fs::path EncodedCache::get_path() {
+	return fs::path(config::vm["audist.cache_dir"].as<std::string>()) / hash;
+}
+
+void EncodedCache::create_cache() {
+	fs::path path = get_path();
+
+	// TODO: Locking?
+	fs::ofstream os(path, std::ios::out | std::ios::binary);
+	// TODO: Make an encoder-to-istream adapter to get rid of this:
+
+	if(!os.is_open())
+		throw std::runtime_error("failed to create cache object");
+	char data[0x10000];
+	std::streamsize size = 1;
+	while(size) {
+		size = encoder->read(data, 0x10000);
+		if(size > 0)
+			os.write(data, size);
+	}
+	os.close();
+}
-- 
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