Use IPFS url in metadata for source links.

Author: chriseth

libsolidity/interface/CompilerStack.cpp

@@ -56,6 +56,7 @@
 #include <libevmasm/Exceptions.h>
 
 #include <libdevcore/SwarmHash.h>
+#include <libdevcore/IpfsHash.h>
 #include <libdevcore/JSON.h>
 
 #include <json/json.h>
@@ -769,6 +770,14 @@ h256 const& CompilerStack::Source::swarmHash() const
 	return swarmHashCached;
 }
 
+string const& CompilerStack::Source::ipfsUrl() const
+{
+	if (ipfsUrlCached.empty())
+		if (scanner->source().size() < 1025 * 256)
+			ipfsUrlCached = "dweb:/ipfs/" + dev::ipfsHashBase58(scanner->source());
+	return ipfsUrlCached;
+}
+
 StringMap CompilerStack::loadMissingSources(SourceUnit const& _ast, std::string const& _sourcePath)
 {
 	solAssert(m_stackState < ParsingSuccessful, "");
@@ -1029,6 +1038,7 @@ string CompilerStack::createMetadata(Contract const& _contract) const
 		{
 			meta["sources"][s.first]["urls"] = Json::arrayValue;
 			meta["sources"][s.first]["urls"].append("bzzr://" + toHex(s.second.swarmHash().asBytes()));
+			meta["sources"][s.first]["urls"].append(s.second.ipfsUrl());
 		}
 	}
 

libsolidity/interface/CompilerStack.h

@@ -272,9 +272,11 @@ class CompilerStack: boost::noncopyable
 		std::shared_ptr<SourceUnit> ast;
 		h256 mutable keccak256HashCached;
 		h256 mutable swarmHashCached;
+		std::string mutable ipfsUrlCached;
 		void reset() { *this = Source(); }
 		h256 const& keccak256() const;
 		h256 const& swarmHash() const;
+		std::string const& ipfsUrl() const;
 	};
 
 	/// The state per contract. Filled gradually during compilation.