func()

in cpc/cpc_compressed_state.go [366:412]

• 37 lines of code
• 10 McCabe index (conditional complexity)

func (c *CpcCompressedState) uncompressPinnedFlavor(src *CpcSketch) error {
	// The pinned flavor must have a non-nil cwStream.
	if c.CwStream == nil {
		return fmt.Errorf("uncompressPinnedFlavor: expected cwStream to be non-nil")
	}
	// Uncompress the window portion into the target sketch.
	if err := uncompressTheWindow(src, c); err != nil {
		return err
	}

	srcLgK := c.LgK
	numPairs := int(c.NumCsv)
	if numPairs == 0 {
		// If there are no pairs, create an empty pair table.
		pt, err := NewPairTable(2, 6+srcLgK)
		if err != nil {
			return err
		}
		src.pairTable = pt
	} else {
		// For pinned flavor, csvStream must be non-nil.
		if c.CsvStream == nil {
			return fmt.Errorf("uncompressPinnedFlavor: expected csvStream to be non-nil")
		}
		// Uncompress the surprising values.
		pairs, err := uncompressTheSurprisingValues(c)
		if err != nil {
			return err
		}
		// Undo the compressor's 8-column shift:
		// For each pair, the lower 6 bits (the column) must be less than 56.
		// Then add 8 back.
		for i := 0; i < numPairs; i++ {
			if (pairs[i] & 63) >= 56 {
				return fmt.Errorf("uncompressPinnedFlavor: invalid pair value %d at index %d", pairs[i], i)
			}
			pairs[i] += 8
		}
		// Create a new pair table from the corrected pairs array.
		table, err := newInstanceFromPairsArray(pairs, numPairs, srcLgK)
		if err != nil {
			return err
		}
		src.pairTable = table
	}
	return nil
}