Extracting non-decoder changes from the decoder PR (#45546)

* creating class

* replacing encoder constants with new class constants

* adding fromValue to StructuredMessageFlags

* updating module info to contain more packages

* style

* undoing module info change

Author: ibrandes

sdk/storage/azure-storage-common/src/main/java/com/azure/storage/common/implementation/structuredmessage/StructuredMessageConstants.java

@@ -0,0 +1,29 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.azure.storage.common.implementation.structuredmessage;
+
+/**
+ * Constants used in the structured message encoding and decoding process.
+ */
+public final class StructuredMessageConstants {
+    /**
+     * The default version of the structured message.
+     */
+    public static final int DEFAULT_MESSAGE_VERSION = 1;
+
+    /**
+     * The length of the header for version 1 of the structured message.
+     */
+    public static final int V1_HEADER_LENGTH = 13;
+
+    /**
+     * The length of the segment header for version 1 of the structured message.
+     */
+    public static final int V1_SEGMENT_HEADER_LENGTH = 10;
+
+    /**
+     * The length of the CRC64 checksum.
+     */
+    public static final int CRC64_LENGTH = 8;
+}

sdk/storage/azure-storage-common/src/main/java/com/azure/storage/common/implementation/structuredmessage/StructuredMessageEncoder.java

@@ -14,14 +14,15 @@
 import java.util.HashMap;
 import java.util.Map;
 
+import static com.azure.storage.common.implementation.structuredmessage.StructuredMessageConstants.CRC64_LENGTH;
+import static com.azure.storage.common.implementation.structuredmessage.StructuredMessageConstants.DEFAULT_MESSAGE_VERSION;
+import static com.azure.storage.common.implementation.structuredmessage.StructuredMessageConstants.V1_HEADER_LENGTH;
+import static com.azure.storage.common.implementation.structuredmessage.StructuredMessageConstants.V1_SEGMENT_HEADER_LENGTH;
+
 /**
  * Encoder for structured messages with support for segmenting and CRC64 checksums.
  */
 public class StructuredMessageEncoder {
-    private static final int DEFAULT_MESSAGE_VERSION = 1;
-    private static final int V1_HEADER_LENGTH = 13;
-    private static final int V1_SEGMENT_HEADER_LENGTH = 10;
-    private static final int CRC64_LENGTH = 8;
     private static final ClientLogger LOGGER = new ClientLogger(StructuredMessageEncoder.class);
 
     private final int messageVersion;

sdk/storage/azure-storage-common/src/main/java/com/azure/storage/common/implementation/structuredmessage/StructuredMessageFlags.java

@@ -45,6 +45,21 @@ public static StructuredMessageFlags fromString(String value) {
         return null;
     }
 
+    /**
+     * Parses a serialized value to a StructuredMessageFlags instance.
+     * @param value the serialized value to parse.
+     * @return the parsed StructuredMessageFlags object.
+     * @throws IllegalArgumentException if unable to parse.
+     */
+    public static StructuredMessageFlags fromValue(int value) {
+        for (StructuredMessageFlags flag : StructuredMessageFlags.values()) {
+            if (flag.getValue() == value) {
+                return flag;
+            }
+        }
+        throw new IllegalArgumentException("Invalid value for StructuredMessageFlags: " + value);
+    }
+
     /**
      * Returns the value for a StructuredMessageFlags instance.
      *