Class Definition

MultiModuleLoggingFramework()

• The framework starts with an empty buffer and no written logs.
• The framework supports both "FILE" and "TOOL" destinations.

Method Signatures

Submit an Activity Log

String logActivity(long sequenceNumber, String moduleName, String destinationType, String logLevel, String logData)

• sequenceNumber is a positive identifier supplied by the module.
• sequenceNumber must be unique across all logs in the framework.
• Sequence numbers do not need to be consecutive or submitted in increasing order.
• moduleName must be "MODULE1", "MODULE2", or "MODULE3".
• destinationType must be "FILE" or "TOOL".
• logLevel must be "INFO", "WARNING", or "ERROR".
• logData contains the activity information to be logged.
  It doesn't contain comma character for consistency.
• After the log has been written successfully, return "ACK,sequenceNumber".
• Return "REJECTED" if any input is invalid or the sequence number has already been used.
• A rejected log is not written to any destination.

Fetch Logs

List<String> getLogs(String destinationType, String moduleName, String logLevel, long minimumSequenceNumber, long maximumSequenceNumber)

• Return logs whose sequence numbers are between minimumSequenceNumber and maximumSequenceNumber, inclusive.
• Use "FILE" or "TOOL" to filter by destination. Use "ALL" to include both destinations.
• Use a supported module name to filter by module. Use "ALL" to include every module.
• Use a supported log level to filter by level. Use "ALL" to include every log level.
• A log is returned only when it satisfies every supplied filter.
• Return matching logs in increasing sequence number order.
• Represent each returned log as "sequenceNumber,destinationType,moduleName,logLevel,logData".
• Return an empty list when no log matches the filters.

Logging Rules

• Every accepted sequence number must be unique.
• Each accepted log must be written exactly once.
• An acknowledgement is returned only after the corresponding log has been written.
• Logs may be submitted in any sequence-number order.
• Rejected logs must not appear in retrieval results.
• Retrieval results are always sorted by increasing sequence number.
• Commas in logData are preserved as part of the activity data.

Constraints

• 1 ≤ sequenceNumber ≤ 1,000,000,000
• moduleName is "MODULE1", "MODULE2", or "MODULE3".
• destinationType is "FILE" or "TOOL" when submitting a log.
• destinationType is "FILE", "TOOL", or "ALL" when fetching logs.
• logLevel is "INFO", "WARNING", or "ERROR" when submitting a log.
• logLevel may also be "ALL" when fetching logs.
• 1 ≤ logData.length() ≤ 10,000
• 1 ≤ minimumSequenceNumber ≤ maximumSequenceNumber ≤ 1,000,000,000
• At most 100,000 logs are submitted to one framework instance.

Example 1

Example 2

Example 3