redis.ts#

This module manages the application's connection to Redis and provides functions for caching and tracking moderation-related data. It plays a crucial role in preventing duplicate moderation actions and in implementing time-windowed rules (like account thresholds).

Note: There is a file with the same name at src/automod/redis.ts. This file appears to be a duplicate or an older version. The one in src/common/ seems to be the one that is actually used.

Redis Client Setup#

• A single redisClient is created using the REDIS_URL from the configuration.
• Event listeners are attached to the client to log connection status (connect, ready), errors (error), and reconnections (reconnecting).

Connection Management#

connectRedis(): Promise<void>#

• Asynchronously connects the redisClient to the Redis server.
• Called once at application startup in main.ts.

disconnectRedis(): Promise<void>#

• Gracefully quits the Redis connection.
• Called during the application's shutdown sequence in main.ts.

Caching and Claiming Functions#

These functions are used to ensure that a specific moderation action (like labeling a post or commenting on an account) is only performed once. They work by setting a key in Redis with an NX (Not Exists) flag, which is an atomic operation.

tryClaimPostLabel(atURI: string, label: string): Promise<boolean>#

• Purpose: To prevent applying the same label to the same post multiple times.
• Key: post-label:<atURI>:<label>
• Logic: Attempts to set the key. If successful (the key didn't already exist), it returns true. Otherwise, it returns false.
• TTL: The key is set to expire in 7 days.
• Error Handling: If the Redis command fails, it logs a warning and returns true to "fail open," allowing the moderation action to proceed.

tryClaimAccountLabel(did: string, label: string): Promise<boolean>#

• Purpose: To prevent applying the same label to the same account multiple times.
• Key: account-label:<did>:<label>
• Logic: Same as tryClaimPostLabel.
• TTL: 7 days.

tryClaimAccountComment(did: string, atURI: string): Promise<boolean>#

• Purpose: To prevent adding the same comment to an account's moderation record multiple times.
• Key: account-comment:<did>:<atURI>
• Logic: Same as the label claiming functions.
• TTL: 7 days.

deleteAccountLabelClaim(did: string, label: string): Promise<void>#

• Purpose: To explicitly remove an account label claim from the cache. This is used when a label is negated (removed) from an account, allowing it to be potentially re-applied later.
• Key: account-label:<did>:<label>
• Logic: Deletes the specified key from Redis.

Time Window Helpers#

Internal helper functions for converting window configurations to Redis-compatible values:

windowToMicroseconds(window: number, unit: WindowUnit): number#

• Purpose: Converts a window duration and unit into microseconds for sorted set scoring.
• Units: minutes, hours, days

windowToSeconds(window: number, unit: WindowUnit): number#

• Purpose: Converts a window duration and unit into seconds for TTL calculations.

Account Threshold Tracking#

These functions provide the mechanism for the accountThreshold.ts module to count how many times an account has had its posts labeled within a rolling time window.

trackPostLabelForAccount(did: string, label: string, timestamp: number, window: number, windowUnit: WindowUnit): Promise<void>#

• Purpose: To record that a post by a specific user received a certain label at a specific time.
• Key: account-post-labels:<did>:<label>:<window><windowUnit> (e.g., account-post-labels:did:plc:xyz:spam:7days)
• Logic:
  1. It uses a Redis Sorted Set (ZADD).
  2. The score of each member in the set is the timestamp of the labeling event (in microseconds).
  3. The value is also the timestamp (it just needs to be unique).
  4. Before adding the new entry, it removes any old entries that are outside the rolling window period (ZREMRANGEBYSCORE).
  5. It sets a TTL on the key (window duration + 1 hour buffer) to ensure it eventually expires if the user stops receiving labels.

getPostLabelCountInWindow(did: string, labels: string[], window: number, windowUnit: WindowUnit, currentTime: number): Promise<number>#

• Purpose: To count how many labels (matching the labels array) an account has received within the rolling window.
• Logic:
  1. It iterates through the provided labels.
  2. For each label, it constructs the appropriate key.
  3. It uses ZCOUNT on the sorted set to count the number of entries whose score (timestamp) is within the desired window.
  4. It sums the counts for all labels and returns the total.

Starter Pack Threshold Tracking#

These functions provide the mechanism for the starterPackThreshold.ts module to count how many starter packs an account has created within a rolling time window.

trackStarterPackForAccount(did: string, starterPackUri: string, timestamp: number, window: number, windowUnit: WindowUnit): Promise<void>#

• Purpose: To record that a user created a starter pack at a specific time.
• Key: starterpack:threshold:<did>:<window><windowUnit> (e.g., starterpack:threshold:did:plc:xyz:7days)
• Logic:
  1. It uses a Redis Sorted Set (ZADD).
  2. The score of each member in the set is the timestamp of the creation event (in microseconds).
  3. The value is the starter pack URI (unique per creation).
  4. Before adding the new entry, it removes any old entries that are outside the rolling window period (ZREMRANGEBYSCORE).
  5. It sets a TTL on the key (window duration + 1 hour buffer) to ensure it eventually expires.

getStarterPackCountInWindow(did: string, window: number, windowUnit: WindowUnit, currentTime: number): Promise<number>#

• Purpose: To count how many starter packs an account has created within the rolling window.
• Logic:
  1. It constructs the key for the account's starter pack tracking set.
  2. It uses ZCOUNT on the sorted set to count the number of entries whose score (timestamp) is within the desired window.
  3. Returns the count.