update

src/msghandler.jl

@@ -723,75 +723,6 @@ function _serialize_data(data::Any, payload_type::String)
 end
 
 
-# """ publish_message - Publish message via transport
-# This function publishes a message via the transport with proper
-# connection management and logging.
-
-# # Arguments:
-#   - `broker_url::String` - Broker URL (e.g., "localhost:4222")
-#   - `subject::String` - Subject to publish to (e.g., "/agent/wine/api/v1/prompt")
-#   - `message::String` - JSON message to publish
-#   - `correlation_id::String` - Correlation ID for tracing and logging
-
-# # Return:
-#   - `nothing` - This function performs publishing but returns nothing
-
-# # Example
-# ```jldoctest
-# using NATS
-
-# # Prepare JSON message
-# message = "{\"correlation_id\":\"abc123\",\"payload\":\"test\"}"
-
-# # Publish via transport
-# publish_message("localhost:4222", "my.subject", message, "abc123")
-# ```
-# """
-# function publish_message(broker_url::String, subject::String, message::String, correlation_id::String)
-#   conn = NATS.connect(broker_url)  # Create NATS connection
-#   publish_message(conn, subject, message, correlation_id)
-# end
-
-# """ publish_message - Publish message via transport using pre-existing connection
-# This function publishes a message via the transport using a pre-existing connection,
-# avoiding the overhead of connection establishment.
-
-# # Arguments:
-#   - `conn` - Pre-existing connection object with publish/close methods
-#   - `subject::String` - Subject to publish to (e.g., "/agent/wine/api/v1/prompt")
-#   - `message::String` - JSON message to publish
-#   - `correlation_id::String` - Correlation ID for tracing and logging
-
-# # Return:
-#   - `nothing` - This function performs publishing but returns nothing
-
-# # Example
-# ```jldoctest
-# using NATS
-
-# # Prepare JSON message
-# message = "{\"correlation_id\":\"abc123\",\"payload\":\"test\"}"
-
-# # Create connection once and reuse for multiple publishes
-# conn = NATS.connect("nats://localhost:4222")
-# publish_message(conn, "my.subject", message, "abc123")
-# # Connection is automatically drained after publish
-# ```
-
-# # Use Case:
-# Use this version when you already have an established connection and want to publish
-# multiple messages without the overhead of creating a new connection for each publish.
-# """
-# function publish_message(conn::NATS.Connection, subject::String, message::String, correlation_id::String)
-#   try
-#     NATS.publish(conn, subject, message)  # Publish message to NATS
-#     log_trace(correlation_id, "Message published to $subject")  # Log successful publish
-#   finally
-#     NATS.drain(conn)  # Ensure connection is closed properly
-#   end
-# end
-
-
 """ smartunpack - Receive and process messages
 This function processes incoming messages, handling both direct transport
 (base64 decoded payloads) and link transport (URL-based payloads).
@@ -809,7 +740,7 @@ A HTTP file server is required along with its download function.
    - `msg_json_str::String` - JSON string from the message payload (e.g., `String(msg.payload)`)
 
 # Keyword Arguments:
-  - `fileserver_download_handler::Function = _fetch_with_backoff` - Function to handle downloading data from file server URLs
+  - `fileserver_download_handler::Function = _fetch_with_backoff` - Custom download handler with signature `handler(url::String, max_retries::Int, base_delay::Int, max_delay::Int, correlation_id::String)::Vector{UInt8}`. Must accept the download URL, retry/backoff parameters, and correlation ID; return the fetched data as `Vector{UInt8}` bytes.
   - `max_retries::Int = 5` - Maximum retry attempts for fetching URL
   - `base_delay::Int = 100` - Initial delay for exponential backoff in ms
   - `max_delay::Int = 5000` - Maximum delay for exponential backoff in ms
@@ -823,6 +754,23 @@ A HTTP file server is required along with its download function.
 msg_json_str = String(msg.payload)
 env = smartunpack(msg_json_str; fileserver_download_handler=_fetch_with_backoff, max_retries=5, base_delay=100, max_delay=5000)
 # env["payloads"] = [("dataname1", data1, "type1"), ("dataname2", data2, "type2"), ...]
+
+# Custom fileserver download handler (e.g., for AWS S3 presigned URLs)
+function my_custom_download(url::String, max_retries::Int, base_delay::Int, max_delay::Int, correlation_id::String)::Vector{UInt8}
+  # Fetch data from `url` with retry logic using exponential backoff
+  # Return the response body as Vector{UInt8} bytes
+  # Example:
+  #   for attempt in 1:max_retries
+  #     resp = HTTP.request("GET", url)
+  #     if resp.status == 200
+  #       return resp.body
+  #     end
+  #   end
+  throw(NotImplementedError("implement download logic here"))
+end
+
+# Use custom download handler
+env = smartunpack(msg_json_str; fileserver_download_handler=my_custom_download)
 ```
 """
 function smartunpack(