Added comments for implementation

ambry-api/src/main/java/com/github/ambry/clustermap/FileStoreException.java

@@ -12,25 +12,53 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  */
 
-
 package com.github.ambry.clustermap;
 
-public class FileStoreException extends RuntimeException{
+/**
+ * Custom exception class for FileStore-related errors.
+ * Extends RuntimeException to allow unchecked exception handling.
+ * Includes specific error codes for different failure scenarios.
+ */
+public class FileStoreException extends RuntimeException {
 
+  // Ensures proper serialization across JVM versions
   private static final long serialVersionUID = 1L;
+
+  // Stores the specific error code associated with this exception
   private final FileStoreErrorCode error;
 
+  /**
+   * Creates a new FileStoreException with a message and error code.
+   * 
+   * @param s The error message describing what went wrong
+   * @param error The specific error code categorizing the failure
+   */
   public FileStoreException(String s, FileStoreErrorCode error) {
     super(s);
     this.error = error;
   }
 
+  /**
+   * Creates a new FileStoreException with a message, error code, and cause.
+   * 
+   * @param s The error message describing what went wrong
+   * @param error The specific error code categorizing the failure
+   * @param throwable The underlying cause of this exception
+   */
   public FileStoreException(String s, FileStoreErrorCode error, Throwable throwable) {
     super(s, throwable);
     this.error = error;
   }
 
-  public enum FileStoreErrorCode{
+  /**
+   * Enumeration of possible FileStore error codes.
+   * Each code represents a specific category of failure.
+   */
+  public enum FileStoreErrorCode {
+    /**
+     * Indicates that the FileStore service is not in running state
+     * when an operation was attempted.
+     */
     FileStoreRunningFailure
   }
 }

ambry-api/src/main/java/com/github/ambry/config/FileCopyConfig.java

@@ -12,36 +12,74 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  */
 
-
 package com.github.ambry.config;
 
+/**
+ * Configuration parameters for file copy operations in Ambry.
+ * This class manages settings related to:
+ * - Parallel processing
+ * - Thread management
+ * - Timeouts
+ * - Data flushing
+ * - Metadata file naming
+ */
 public class FileCopyConfig {
 
+  /**
+   * Number of partitions that can be hydrated in parallel per disk.
+   * Higher values increase parallelism but also resource usage.
+   */
   public static final String PARALLEL_PARTITION_HYDRATION_COUNT_PER_DISK = "parallel.partition.hydration.count.per.disk";
   @Config(PARALLEL_PARTITION_HYDRATION_COUNT_PER_DISK)
   public final int parallelPartitionHydrationCountPerDisk;
 
+  /**
+   * Number of threads dedicated to file copy operations.
+   * Controls the level of concurrent file transfers.
+   */
   public static final String NUMBER_OF_FILE_COPY_THREADS = "number.of.file.copy.threads";
   @Config(NUMBER_OF_FILE_COPY_THREADS)
   public final int numberOfFileCopyThreads;
 
+  /**
+   * Timeout duration for file chunk operations in minutes.
+   * After this duration, incomplete chunk operations are considered failed.
+   */
   public static final String FILE_CHUNK_TIMEOUT_IN_MINUTES = "file.chunk.timeout.in.minutes";
   @Config(FILE_CHUNK_TIMEOUT_IN_MINUTES)
   public final long fileChunkTimeoutInMins;
 
   /**
-   * The frequency at which the data gets flushed to disk
+   * The frequency at which data gets flushed to disk in megabytes.
+   * Lower values increase durability but may impact performance.
+   * Default: 1000MB
    */
   public static final String STORE_DATA_FLUSH_INTERVAL_IN_MBS = "store.data.flush.interval.In.MBs";
   @Config(STORE_DATA_FLUSH_INTERVAL_IN_MBS)
   @Default("1000")
   public final long storeDataFlushIntervalInMbs;
 
+  /**
+   * Name of the metadata file used for file copy operations.
+   * This file stores information about sealed logs and their associated metadata.
+   * Default: "sealed_logs_metadata_file"
+   */
   public static final String FILE_COPY_META_DATA_FILE_NAME = "file.copy.meta.data.file.name";
   @Config(FILE_COPY_META_DATA_FILE_NAME)
   @Default("sealed_logs_metadata_file")
   public final String fileCopyMetaDataFileName;
 
+  /**
+   * Creates a new FileCopyConfig with the provided properties.
+   * 
+   * @param verifiableProperties Properties containing configuration values
+   *        If a property is not specified, default values are used:
+   *        - parallelPartitionHydrationCountPerDisk: 1
+   *        - numberOfFileCopyThreads: 4
+   *        - fileChunkTimeoutInMins: 5
+   *        - storeDataFlushIntervalInMbs: 1000
+   *        - fileCopyMetaDataFileName: "sealed_logs_metadata_file"
+   */
   public FileCopyConfig(VerifiableProperties verifiableProperties) {
     fileCopyMetaDataFileName = verifiableProperties.getString(FILE_COPY_META_DATA_FILE_NAME, "sealed_logs_metadata_file");
     parallelPartitionHydrationCountPerDisk = verifiableProperties.getInt(PARALLEL_PARTITION_HYDRATION_COUNT_PER_DISK, 1);

ambry-api/src/main/java/com/github/ambry/store/FileInfo.java

@@ -14,22 +14,54 @@
 
 package com.github.ambry.store;
 
+/**
+ * Represents metadata about a file in the Ambry storage system.
+ * Contains basic file information like name and size.
+ * Used for tracking file details during copy operations and metadata management.
+ */
 public class FileInfo {
+  // Name of the file, including any path components
   private String fileName;
+
+  // Size of the file in bytes
+  // Marked final as size shouldn't change after creation
   private final long fileSize;
 
+  /**
+   * Creates a new FileInfo instance.
+   * 
+   * @param fileName Name or path of the file
+   * @param fileSize Size of the file in bytes
+   */
   public FileInfo(String fileName, Long fileSize) {
     this.fileName = fileName;
     this.fileSize = fileSize;
   }
+
+  /**
+   * Gets the name of the file.
+   * 
+   * @return The file name or path
+   */
   public String getFileName() {
     return fileName;
   }
 
+  /**
+   * Gets the size of the file in bytes.
+   * 
+   * @return The file size
+   */
   public Long getFileSize() {
     return fileSize;
   }
 
+  /**
+   * Returns a string representation of the FileInfo object.
+   * Useful for logging and debugging.
+   * 
+   * @return String containing file name and size
+   */
   @Override
   public String toString() {
     return "FileInfo{" +

ambry-api/src/main/java/com/github/ambry/store/LogInfo.java

@@ -12,47 +12,102 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  */
 
-
 package com.github.ambry.store;
 
 import java.util.List;
 
-
+/**
+ * Represents information about a log segment and its associated metadata files.
+ * Contains details about:
+ * - The sealed log segment
+ * - Associated index segments
+ * - Bloom filters for efficient lookups
+ */
 public class LogInfo {
+  // The sealed log segment containing the actual data
   FileInfo sealedSegment;
+
+  // List of index segments associated with this log
+  // Each index segment provides lookup capabilities for a portion of the log
   List<FileInfo> indexSegments;
+
+  // List of bloom filters for efficient key lookups
+  // Each bloom filter corresponds to an index segment
   List<FileInfo> bloomFilters;
 
+  /**
+   * Creates a new LogInfo instance with the specified components.
+   * 
+   * @param sealedSegment The sealed log segment file information
+   * @param indexSegments List of index segment file information
+   * @param bloomFilters List of bloom filter file information
+   */
   public LogInfo(FileInfo sealedSegment, List<FileInfo> indexSegments, List<FileInfo> bloomFilters) {
     this.sealedSegment = sealedSegment;
     this.indexSegments = indexSegments;
     this.bloomFilters = bloomFilters;
   }
 
+  /**
+   * Gets the sealed log segment information.
+   * 
+   * @return FileInfo for the sealed log segment
+   */
   public FileInfo getSealedSegment() {
     return sealedSegment;
   }
 
+  /**
+   * Sets the sealed log segment information.
+   * 
+   * @param sealedSegments New sealed segment information
+   */
   public void setSealedSegments(FileInfo sealedSegments) {
     this.sealedSegment = sealedSegments;
   }
 
+  /**
+   * Gets the list of index segment information.
+   * 
+   * @return List of FileInfo objects for index segments
+   */
   public List<FileInfo> getIndexSegments() {
     return indexSegments;
   }
 
+  /**
+   * Sets the list of index segment information.
+   * 
+   * @param indexSegments New list of index segment information
+   */
   public void setIndexSegments(List<FileInfo> indexSegments) {
     this.indexSegments = indexSegments;
   }
 
+  /**
+   * Gets the list of bloom filter information.
+   * 
+   * @return List of FileInfo objects for bloom filters
+   */
   public List<FileInfo> getBloomFilters() {
     return bloomFilters;
   }
 
+  /**
+   * Sets the list of bloom filter information.
+   * 
+   * @param bloomFilters New list of bloom filter information
+   */
   public void setBloomFilters(List<FileInfo> bloomFilters) {
     this.bloomFilters = bloomFilters;
   }
 
+  /**
+   * Returns a string representation of the LogInfo object.
+   * Useful for logging and debugging.
+   * 
+   * @return String containing details of sealed segment, index segments, and bloom filters
+   */
   @Override
   public String toString() {
     return "LogInfo{" +

ambry-protocol/src/main/java/com/github/ambry/protocol/LogInfo.java

@@ -1,5 +1,5 @@
 /**
- * Copyright 2025 LinkedIn Corp. All rights reserved.
+ * Copyright 2024 LinkedIn Corp. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -11,7 +11,6 @@
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  */
-
 package com.github.ambry.protocol;
 
 import com.github.ambry.utils.Utils;

ambry-server/src/main/java/com/github/ambry/server/AmbryServer.java

@@ -43,7 +43,6 @@
 import com.github.ambry.config.ClusterMapConfig;
 import com.github.ambry.config.ConnectionPoolConfig;
 import com.github.ambry.config.DiskManagerConfig;
-import com.github.ambry.config.FileCopyConfig;
 import com.github.ambry.config.Http2ClientConfig;
 import com.github.ambry.config.NettyConfig;
 import com.github.ambry.config.NetworkConfig;