Providence Utils: Logging

Basic message helpers for creating and managing running structured logs of providence messages.

Since using the Serializers require knowing more about the source of and how to handle multiple message in one etc. This interface is mostly a simplification of use of the Serializers, making specialized MessageReader and MessageWriter classes.

• IOMessageReader and IOMessageWriter are simply wrappers around input stream and output stream that handles streaming multiple messages, with optional internal separators (e.g. for JSON).
• FileMessageReader and FileMessageWriter writes to and reads from a single file that is appended to and read from as a stream of messages, also with optional internal separators.

On the more log-based utilities, we have:

• QueuedMessageQriter that uses an in memory message queue and handles the actual write operations in a separate thread. This should make using the other logging writers more palatable in latency critical operations.
• RollingFileMessageWriter writes to file as FileMessageWriter, but handles rolling policy (when a new log file should be created), and cleanup policy (when an old log file should be deleted).

There are also a general utility for creating loggable strings based on a coded manual setup, LogFormatter.