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67 lines
2.4 KiB
67 lines
2.4 KiB
9 years ago
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// Package erasure is a Go wrapper for the Intel Intelligent Storage
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// Acceleration Library (Intel ISA-L). Intel ISA-L is a CPU optimized
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// implementation of erasure coding algorithms.
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//
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// For more information on Intel ISA-L, please visit:
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// https://01.org/intel%C2%AE-storage-acceleration-library-open-source-version
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//
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// Usage:
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//
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// Encode encodes a block of data. The input is the original data. The output
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// is a 2 tuple containing (k + m) chunks of erasure encoded data and the
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// length of the original object.
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//
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// Decode decodes 2 tuple data containing (k + m) chunks back into its original form.
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// Additionally original block length should also be provided as input.
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//
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// Decoded data is exactly similar in length and content as the original data.
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//
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// Encoding data may be performed in 3 steps.
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//
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// 1. Create a parse set of encoder parameters
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// 2. Create a new encoder
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// 3. Encode data
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//
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// Decoding data is also performed in 3 steps.
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//
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// 1. Create a parse set of encoder parameters for validation
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// 2. Create a new encoder
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// 3. Decode data
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//
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// Erasure parameters contain three configurable elements:
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// ValidateParams(k, m, technique int) (ErasureParams, error)
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// k - Number of rows in matrix
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// m - Number of colums in matrix
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// technique - Matrix type, can be either Cauchy (recommended) or Vandermonde
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// constraints: k + m < Galois Field (2^8)
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//
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// Choosing right parity and matrix technique is left for application to decide.
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//
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// But here are the few points to keep in mind
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//
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// Matrix Type:
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// - Vandermonde is most commonly used method for choosing coefficients in erasure
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// encoding but does not guarantee invertable for every sub matrix.
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// - Whereas Cauchy is our recommended method for choosing coefficients in erasure coding.
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// Since any sub-matrix of a Cauchy matrix is invertable.
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//
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// Total blocks:
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// - Data blocks and Parity blocks should not be greater than 'Galois Field' (2^8)
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//
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// Example
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//
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// Creating and using an encoder
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// var bytes []byte
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// params := erasure.ValidateParams(10, 5)
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// encoder := erasure.NewErasure(params)
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// encodedData, length := encoder.Encode(bytes)
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//
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// Creating and using a decoder
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// var encodedData [][]byte
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// var length int
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// params := erasure.ValidateParams(10, 5)
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// encoder := erasure.NewErasure(params)
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// originalData, err := encoder.Decode(encodedData, length)
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//
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package erasure
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