add WriteCompressedFile RPC for compressed file transfers to HordeAgent

Implements the client/initiator side of the WriteCompressedFile protocol,
enabling efficient file uploads to Horde agents with IoHash-based caching.
The agent can skip data transfer entirely on cache hits, and files are
sent as chunked compressed buffer (.ucb) streams on cache misses.

1 files changed, 43 insertions, 0 deletions

diff --git a/src/zenhorde/hordeagentmessage.cpp b/src/zenhorde/hordeagentmessage.cpp
index 998134a96..541fd8851 100644
--- a/src/zenhorde/hordeagentmessage.cpp
+++ b/src/zenhorde/hordeagentmessage.cpp
@@ -131,6 +131,34 @@ AgentMessageChannel::Blob(const uint8_t* Data, size_t Length)
 	}
 }
 
+void
+AgentMessageChannel::SendWriteCompressedFile(std::string_view Path, int64_t CompressedSize, const IoHash& UncompressedHash)
+{
+	const size_t MaxLength = MeasureUnsignedVarInt(Path.size()) + Path.size() + sizeof(int64_t) + sizeof(UncompressedHash.Hash);
+	CreateMessage(AgentMessageType::WriteCompressedFile, MaxLength);
+	WriteString(Path);
+	WriteInt64(CompressedSize);
+	WriteFixedLengthBytes(UncompressedHash.Hash, sizeof(UncompressedHash.Hash));
+	FlushMessage();
+}
+
+void
+AgentMessageChannel::SendWriteCompressedFileData(int32_t Offset, const uint8_t* Data, size_t Length)
+{
+	CreateMessage(AgentMessageType::WriteCompressedFileData, sizeof(int32_t) + Length);
+	WriteInt32(Offset);
+	WriteFixedLengthBytes(Data, Length);
+	FlushMessage();
+}
+
+bool
+AgentMessageChannel::ReadWriteCompressedFileResponse()
+{
+	assert(m_ResponseType == AgentMessageType::WriteCompressedFileResponse);
+	assert(m_ResponseLength >= 1);
+	return m_ResponseData[0] != 0;
+}
+
 AgentMessageType
 AgentMessageChannel::ReadResponse(int32_t TimeoutMs, bool* OutTimedOut)
 {
@@ -229,6 +257,21 @@ AgentMessageChannel::ReadInt32(const uint8_t** Pos)
 }
 
 void
+AgentMessageChannel::WriteInt64(int64_t Value)
+{
+	WriteFixedLengthBytes(reinterpret_cast<const uint8_t*>(&Value), sizeof(int64_t));
+}
+
+int64_t
+AgentMessageChannel::ReadInt64(const uint8_t** Pos)
+{
+	int64_t Value;
+	memcpy(&Value, *Pos, sizeof(int64_t));
+	*Pos += sizeof(int64_t);
+	return Value;
+}
+
+void
 AgentMessageChannel::WriteFixedLengthBytes(const uint8_t* Data, size_t Length)
 {
 	assert(m_RequestSize + Length <= m_MaxRequestSize);