Merge pull request #2 from PhonePe/oss

Open Source DLM

.github/workflows/sonarcloud-checks.yml

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+name: SonarCloud
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    types: [opened, synchronize, reopened]
+jobs:
+  build:
+    name: Build and analyze
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0  # Shallow clones should be disabled for a better relevancy of analysis
+      - name: Set up JDK 17
+        uses: actions/setup-java@v3
+        with:
+          java-version: 17
+          distribution: 'zulu' # Alternative distribution options are available.
+      - name: Cache SonarCloud packages
+        uses: actions/cache@v3
+        with:
+          path: ~/.sonar/cache
+          key: ${{ runner.os }}-sonar
+          restore-keys: ${{ runner.os }}-sonar
+      - name: Cache Maven packages
+        uses: actions/cache@v3
+        with:
+          path: ~/.m2
+          key: ${{ runner.os }}-m2-${{ hashFiles('**/pom.xml') }}
+          restore-keys: ${{ runner.os }}-m2
+      - name: Build and analyze
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}  # Needed to get PR information, if any
+          SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
+        run: mvn -B verify org.sonarsource.scanner.maven:sonar-maven-plugin:sonar -Dsonar.projectKey=PhonePe_dlm

.gitignore

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+### Java template
+*.class
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# Package Files #
+*.jar
+*.war
+*.ear
+
+hs_err_pid*
+### JetBrains template
+# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio
+
+## File-based project format:
+*.ipr
+*.iws
+
+## Plugin-specific files:
+
+# IntelliJ
+/out/
+
+# mpeltonen/sbt-idea plugin
+.idea_modules/
+
+# JIRA plugin
+atlassian-ide-plugin.xml
+
+# Crashlytics plugin (for Android Studio and IntelliJ)
+com_crashlytics_export_strings.xml
+crashlytics.properties
+crashlytics-build.properties
+
+## Directory-based project format:
+/.idea/
+/target/
+benchmarking/.idea/
+benchmarking/target/
+.classpath
+.project
+.settings/
+.DS_Store
+*.iml
+
+/bin/

CODE_OF_CONDUCT.md

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+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+In the interest of fostering an open and welcoming environment, we as contributors and maintainers pledge to making participation in our project and our community a harassment-free experience for everyone, regardless of age, body size, disability, ethnicity, gender identity and expression, level of experience, nationality, personal appearance, race, religion, or sexual identity and orientation.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment include:
+
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
+
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery and unwelcome sexual attention or advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or electronic address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable behavior and are expected to take appropriate and fair corrective action in response to any instances of unacceptable behavior.
+
+Project maintainers have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct, or to ban temporarily or permanently any contributor for other behaviors that they deem inappropriate, threatening, offensive, or harmful.
+
+## Scope
+
+This Code of Conduct applies both within project spaces and in public spaces when an individual is representing the project or its community. Examples of representing a project or community include using an official project e-mail address, posting via an official social media account, or acting as an appointed representative at an online or offline event. Representation of a project may be further defined and clarified by project maintainers.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting the project team at [TBD]. The project team will review and investigate all complaints, and will respond in a way that it deems appropriate to the circumstances. The project team is obligated to maintain confidentiality with regard to the reporter of an incident. Further details of specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good faith may face temporary or permanent repercussions as determined by other members of the project's leadership.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4, available at [http://contributor-covenant.org/version/1/4][version]
+
+[homepage]: http://contributor-covenant.org
+[version]: http://contributor-covenant.org/version/1/4/

README.md

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-# DLM
-Distributed Lock Manager
+# Distributed Lock Manager (DLM)
+
+Locking is a very common expectation in SoA, where a vulnerable entity needs to be protected for a certain duration.
+And the definition of vulnerable entity changes from one client to another depending on the use-cases at hand.
+
+Distributed Lock Manager is an easy-to-use library to achieve various modes of locking, be it - Exclusive or Limited Protected(LP).
+In current version, Exclusive locking mode is supported with Aerospike as the underlying storage base by leveraging
+its MVCC (MultiVersion Concurrency Control) capability.
+
+## Add Maven Dependency
+
+```xml
+<dependency>
+  <groupId>com.phonepe</groupId>
+  <artifactId>distributed-lock-manager</artifactId>
+  <version>3.0.6</version>
+</dependency>
+```
+
+
+### Usage
+
+#### Initializing Distributed Lock Manager
+
+##### With Aerospike as lock base
+
+``` java
+DistributedLockManager lockManager = DistributedLockManager.builder()
+                .clientId("CLIENT_ID")
+                .farmId("FA1")
+                .lockBase(AerospikeLockBase.builder()
+                        .mode(LockMode.EXCLUSIVE)
+                        .store(AerospikeStore.builder()
+                                .aerospikeClient(aerospikeClient)
+                                .namespace("NAMESPACE")
+                                .setSuffix("distributed_lock")
+                                .build())
+                        .build())
+                .build();
+lockManager.initialize();
+```
+
+##### With HBase as lock base
+
+``` java
+DistributedLockManager lockManager = DistributedLockManager.builder()
+                .clientId("CLIENT_ID")
+                .farmId("FA1")
+                .lockBase(HBaseLockBase.builder()
+                        .mode(LockMode.EXCLUSIVE)
+                        .store(HBaseStore.builder()
+                                .connection(connection) // HBase connection reference
+                                .tableName("table_name")
+                                .build())
+                        .build())
+                .build();
+lockManager.initialize();
+```
+
+PS : For optimum performance, DO NOT pre-create the HBase table. Library will do it for you.
+
+
+# Entity Lock Management
+
+This library offers various methods for acquiring and releasing locks on critical entities. Below are the available methods:
+
+1. **`tryAcquireLock(lock)`**
+    - Attempts immediate lock acquisition. Throws an exception if the lock is unavailable. Does not wait if the lock is currently held by another thread. The default lock duration is 90 seconds.
+
+2. **`tryAcquireLock(lock, duration)`**
+    - Immediate lock acquisition attempt with a specified duration. Throws an exception if the lock is unavailable. Does not wait if the lock is held by another thread.
+
+3. **`acquireLock(lock)`**
+    - Tries to acquire the lock. If the lock is held by another thread, it waits until the lock becomes available, blocking the thread. The default timeout is 90 seconds, and the lock duration defaults to 90 seconds.
+
+4. **`acquireLock(lock, duration)`**
+    - Similar to `acquireLock(lock)` but allows a specified duration for the lock.
+
+5. **`acquireLock(lock, duration, timeout)`**
+    - Attempts to acquire the lock and waits for a limited time for it to become available. If the lock is not acquired within the given time, it returns with a failure indication. This method blocks the thread until the lock is acquired.
+
+## Example Usage
+
+```java
+// Representing a vulnerable entity by LOCK_ID
+final Lock lock = lockManager.getLockInstance("LOCK_ID", LockLevel.DC);
+try {
+    lockManager.tryAcquireLock(lock); // Attempts to acquire the lock for the default duration of 90 seconds
+    // OR lockManager.tryAcquireLock(lock, 120); // Tries to acquire the lock for 120 seconds
+
+    // Perform actions once the lock is successfully acquired.
+
+} catch (DLSException e) {
+    if (ErrorCode.LOCK_UNAVAILABLE.equals(e.getErrorCode)) {
+        // Actions to take if the lock can't be acquired.
+    }
+} finally {
+    // Verify if the lock was released successfully.
+    boolean released = lockManager.release(lock);
+}
+```
+
+```java
+// Vulnerable entity represented by LOCK_ID
+// Representing a vulnerable entity by LOCK_ID
+final Lock lock = lockManager.getLockInstance("LOCK_ID", LockLevel.DC);
+try {
+    lockManager.acquireLock(lock); // Attempts to acquire the lock for the default duration of 90 seconds and waits for 90 seconds
+    // OR lockManager.acquireLock(lock, 30); // Tries to acquire the lock for 30 seconds, waiting for 90 seconds
+    // OR lockManager.acquireLock(lock, 30, 30); // Tries to acquire the lock for 30 seconds, waiting for 30 seconds
+
+    // Perform actions once the lock is successfully acquired.
+} catch (DLSException e) {
+    if (ErrorCode.LOCK_UNAVAILABLE.equals(e.getErrorCode)) {
+        // Actions to take if the lock can't be acquired.
+    }
+} finally {
+    // Verify if the lock was released successfully.
+    boolean released = lockManager.release(lock);
+}
+```
+
+#### Lock Levels
+* DC - Acquiring/releasing lock within a DC
+* XDC - Acquiring/releasing lock across DCs.
+
+
+**Caution**: Concurrently obtaining a lock on the same entity using XDC across multiple data centers may result in unexpected behavior due to the replication of data between centers. Therefore, it is recommended to utilize DC locks whenever feasible.
+
+For XDC locks requiring strong consistency, opt for a multi-site Aerospike cluster.
+
+#### Notes
+
+A lock exists only within the scope of a Client represented by `CLIENT_ID`.

build.properties

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+BUILD_PROJECT_VERSION=1.0.0

lombok.config

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+lombok.addLombokGeneratedAnnotation = true
+lombok.anyConstructor.addConstructorProperties = true
+config.stopBubbling = true