Implemented

.gitignore

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+target

LICENSE

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+Copyright (c) 2016, S&K Software Development Ltd
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+ * Neither the name of the S&K Software Development Ltd nor the
+ names of its contributors may be used to endorse or promote products
+ derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
+DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

README.md

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+This package implements generic CRC calculations up to 64 bits wide.
+It aims to be fairly fast and fairly complete, allowing users to match pretty much
+any CRC algorithm used in the wild by choosing appropriate Parameters. This obviously 
+includes all popular CRC algorithms, such as CRC64-ISO, CRC64-ECMA, CRC32, CRC32C, CRC16, CCITT, XMODEM and many others.
+See http://reveng.sourceforge.net/crc-catalogue/ for a good list of CRC algorithms and their parameters.
+
+This package has been largely inspired by Ross Williams' 1993 paper "A Painless Guide to CRC Error Detection Algorithms".
+
+
+## Usage
+
+Using src is easy. Here is an example of calculating CCITT crc.
+```java
+import com.github.snksoft.crc.CRC;
+
+public class Example
+{
+ public static void main(String [] args) {
+ String data = "123456789";
+ long ccittCrc = CRC.calculateCRC(CRC.Parameters.CCITT, data.getBytes());
+ System.out.printf("CRC is 0x%04X\n", ccittCrc); // prints "CRC is 0x29B1"
+
+ }
+}
+```
+
+For larger data, table driven implementation is faster. Here is how to use it.
+```java
+import com.github.snksoft.crc.CRC;
+
+public class Example
+{
+ public static void main(String [] args) {
+ String data = "123456789";
+ CRC tableDriven = new CRC(CRC.Parameters.XMODEM);
+ long xmodemCrc = tableDriven.calculateCRC(data.getBytes());
+ System.out.printf("CRC is 0x%04X\n", xmodemCrc); // prints "CRC is 0x31C3"
+
+ // You can also reuse CRC object instance for another crc calculation.
+ // Given that the only state for a CRC calculation is the "intermediate value"
+ // and it is stored in your code, you can even use same CRC instance to calculate CRC
+ // of multiple data sets in parallel.
+ // And if data is too big, you may feed it in chunks
+ long curValue = tableDriven.init(); // initialize intermediate value
+ curValue = tableDriven.update(curValue, "123456789".getBytes()); // feed first chunk
+ curValue = tableDriven.update(curValue, "01234567890".getBytes()); // feed next chunk
+ long xmodemCrc2 = tableDriven.finalCRC(curValue); // gets CRC of whole data ("12345678901234567890")
+ System.out.printf("CRC is 0x%04X\n", xmodemCrc2); // prints "CRC is 0x2C89"
+ }
+}
+```

pom.xml

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+ <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+ <modelVersion>4.0.0</modelVersion>
+
+ <groupId>com.github.snksoft</groupId>
+ <artifactId>java-crc</artifactId>
+ <version>1.0-SNAPSHOT</version>
+ <packaging>jar</packaging>
+
+ <name>Generic CRC implementation for java</name>
+ <url>https://github.com/snksoft/java-crc</url>
+
+ <properties>
+ <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+ <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> 
+ </properties>
+
+ <build>
+ <plugins>
+ <!-- Mandatory plugins for using Spock -->
+ <plugin>
+ <!-- The gmavenplus plugin is used to compile Groovy code. To learn more about this plugin, 
+ visit https://github.com/groovy/GMavenPlus/wiki -->
+ <groupId>org.codehaus.gmavenplus</groupId>
+ <artifactId>gmavenplus-plugin</artifactId>
+ <version>1.4</version>
+ <executions>
+ <execution>
+ <goals>
+ <goal>compile</goal>
+ <goal>testCompile</goal>
+ </goals>
+ </execution>
+ </executions>
+ </plugin>
+ <!-- Optional plugins for using Spock -->
+ <!-- Only required if names of spec classes don't match default Surefire patterns (`*Example` etc.) -->
+ <plugin>
+ <artifactId>maven-surefire-plugin</artifactId>
+ <version>2.6</version>
+ <configuration>
+ <useFile>false</useFile>
+ <includes>
+ <include>**/*Spec.java</include>
+ </includes>
+ </configuration>
+ </plugin>
+ <!-- Only required for spock-example build -->
+ <plugin>
+ <artifactId>maven-deploy-plugin</artifactId>
+ <version>2.5</version>
+ <configuration>
+ <skip>true</skip>
+ </configuration>
+ </plugin>
+ </plugins>
+ </build>
+
+ <dependencies>
+
+ <dependency>
+ <groupId>org.codehaus.groovy</groupId>
+ <artifactId>groovy-all</artifactId>
+ <version>2.4.1</version>
+ <scope>compile</scope>
+ </dependency>
+
+ <dependency>
+ <groupId>org.spockframework</groupId>
+ <artifactId>spock-core</artifactId>
+ <version>1.0-groovy-2.4</version>
+ <scope>compile</scope>
+ </dependency>
+
+ </dependencies>
+
+ </project>
+