Activity - gzipCompression

Activity Type: Transformation

Description

Compress the data output from other activities, using the GNU-ZIP compression format.

Example

<gzipCompression name="transform">
  <settings checksum="adler32"/>
  <input from="myStatementOutput"/>
  <compressedOutput name="myCompressedOutput"/>
  <metadataOutput name="myMetadataOutput"/>
</gzipCompression>

Specification

Element gzipCompression:

• Attribute name - unique name for the activity within the scope of a request.
• Element settings (optional) - the control settings for the compression.
  • Attribute checksum - the type of checksum generate for the compressed data. The checksum can be used for validation purposes. Legal values of the attribute are:
    • adler32 - Adler32 checksum (faster).
    • crc32 - CRC32 checksum.
• Element input (required) - where to find the data to compress.
  • Attribute from - name of an input stream providing data to be compressed.
• compressedOutput (required) - output stream for the compressed data (bytes).
  • Attribute name - name of this output stream.
• metadataOutput (required) - output stream for compression meta-data (XML data including the checksum).
  • Attribute name - name of this output stream.

Input and Output Types

• Input: input - byte[] or java.lang.String or org.w3c.dom.Node
• Output: compressedOutput - java.lang.String
• Output: metadataOutput - java.lang.String (XML)
Example:

<gzipCompressionMetadata>
  <checksum type="adler32" value="620519488"/>
</gzipCompressionMetadata>

Data Resource Accessor

This activity can operate with any data resource accessor.

XML Schema

OGSA-DAI/schema/ogsadai/xsd/activities/gzip_compression.xsd

Class

uk.org.ogsadai.activity.transform.GZIPCompressionActivity

Client Toolkit Class

uk.org.ogsadai.client.toolkit.activity.transform.GZIPCompression