Follow some advice from staticcheck.

cluster_command.go

@@ -1,7 +1,5 @@
 package brotli
 
-import "math"
-
 /* Copyright 2013 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.
@@ -164,163 +162,3 @@ func histogramBitCostDistanceCommand(histogram *histogramCommand, candidate *his
 		return populationCostCommand(&tmp) - candidate.bit_cost_
 	}
 }
-
-/* Find the best 'out' histogram for each of the 'in' histograms.
-   When called, clusters[0..num_clusters) contains the unique values from
-   symbols[0..in_size), but this property is not preserved in this function.
-   Note: we assume that out[]->bit_cost_ is already up-to-date. */
-func histogramRemapCommand(in []histogramCommand, in_size uint, clusters []uint32, num_clusters uint, out []histogramCommand, symbols []uint32) {
-	var i uint
-	for i = 0; i < in_size; i++ {
-		var best_out uint32
-		if i == 0 {
-			best_out = symbols[0]
-		} else {
-			best_out = symbols[i-1]
-		}
-		var best_bits float64 = histogramBitCostDistanceCommand(&in[i], &out[best_out])
-		var j uint
-		for j = 0; j < num_clusters; j++ {
-			var cur_bits float64 = histogramBitCostDistanceCommand(&in[i], &out[clusters[j]])
-			if cur_bits < best_bits {
-				best_bits = cur_bits
-				best_out = clusters[j]
-			}
-		}
-
-		symbols[i] = best_out
-	}
-
-	/* Recompute each out based on raw and symbols. */
-	for i = 0; i < num_clusters; i++ {
-		histogramClearCommand(&out[clusters[i]])
-	}
-
-	for i = 0; i < in_size; i++ {
-		histogramAddHistogramCommand(&out[symbols[i]], &in[i])
-	}
-}
-
-/* Reorders elements of the out[0..length) array and changes values in
-   symbols[0..length) array in the following way:
-     * when called, symbols[] contains indexes into out[], and has N unique
-       values (possibly N < length)
-     * on return, symbols'[i] = f(symbols[i]) and
-                  out'[symbols'[i]] = out[symbols[i]], for each 0 <= i < length,
-       where f is a bijection between the range of symbols[] and [0..N), and
-       the first occurrences of values in symbols'[i] come in consecutive
-       increasing order.
-   Returns N, the number of unique values in symbols[]. */
-
-var histogramReindexCommand_kInvalidIndex uint32 = math.MaxUint32
-
-func histogramReindexCommand(out []histogramCommand, symbols []uint32, length uint) uint {
-	var new_index []uint32 = make([]uint32, length)
-	var next_index uint32
-	var tmp []histogramCommand
-	var i uint
-	for i = 0; i < length; i++ {
-		new_index[i] = histogramReindexCommand_kInvalidIndex
-	}
-
-	next_index = 0
-	for i = 0; i < length; i++ {
-		if new_index[symbols[i]] == histogramReindexCommand_kInvalidIndex {
-			new_index[symbols[i]] = next_index
-			next_index++
-		}
-	}
-
-	/* TODO: by using idea of "cycle-sort" we can avoid allocation of
-	   tmp and reduce the number of copying by the factor of 2. */
-	tmp = make([]histogramCommand, next_index)
-
-	next_index = 0
-	for i = 0; i < length; i++ {
-		if new_index[symbols[i]] == next_index {
-			tmp[next_index] = out[symbols[i]]
-			next_index++
-		}
-
-		symbols[i] = new_index[symbols[i]]
-	}
-
-	new_index = nil
-	for i = 0; uint32(i) < next_index; i++ {
-		out[i] = tmp[i]
-	}
-
-	tmp = nil
-	return uint(next_index)
-}
-
-func clusterHistogramsCommand(in []histogramCommand, in_size uint, max_histograms uint, out []histogramCommand, out_size *uint, histogram_symbols []uint32) {
-	var cluster_size []uint32 = make([]uint32, in_size)
-	var clusters []uint32 = make([]uint32, in_size)
-	var num_clusters uint = 0
-	var max_input_histograms uint = 64
-	var pairs_capacity uint = max_input_histograms * max_input_histograms / 2
-	var pairs []histogramPair = make([]histogramPair, (pairs_capacity + 1))
-	var i uint
-
-	/* For the first pass of clustering, we allow all pairs. */
-	for i = 0; i < in_size; i++ {
-		cluster_size[i] = 1
-	}
-
-	for i = 0; i < in_size; i++ {
-		out[i] = in[i]
-		out[i].bit_cost_ = populationCostCommand(&in[i])
-		histogram_symbols[i] = uint32(i)
-	}
-
-	for i = 0; i < in_size; i += max_input_histograms {
-		var num_to_combine uint = brotli_min_size_t(in_size-i, max_input_histograms)
-		var num_new_clusters uint
-		var j uint
-		for j = 0; j < num_to_combine; j++ {
-			clusters[num_clusters+j] = uint32(i + j)
-		}
-
-		num_new_clusters = histogramCombineCommand(out, cluster_size, histogram_symbols[i:], clusters[num_clusters:], pairs, num_to_combine, num_to_combine, max_histograms, pairs_capacity)
-		num_clusters += num_new_clusters
-	}
-	{
-		/* For the second pass, we limit the total number of histogram pairs.
-		   After this limit is reached, we only keep searching for the best pair. */
-		var max_num_pairs uint = brotli_min_size_t(64*num_clusters, (num_clusters/2)*num_clusters)
-		if pairs_capacity < (max_num_pairs + 1) {
-			var _new_size uint
-			if pairs_capacity == 0 {
-				_new_size = max_num_pairs + 1
-			} else {
-				_new_size = pairs_capacity
-			}
-			var new_array []histogramPair
-			for _new_size < (max_num_pairs + 1) {
-				_new_size *= 2
-			}
-			new_array = make([]histogramPair, _new_size)
-			if pairs_capacity != 0 {
-				copy(new_array, pairs[:pairs_capacity])
-			}
-
-			pairs = new_array
-			pairs_capacity = _new_size
-		}
-
-		/* Collapse similar histograms. */
-		num_clusters = histogramCombineCommand(out, cluster_size, histogram_symbols, clusters, pairs, num_clusters, in_size, max_histograms, max_num_pairs)
-	}
-
-	pairs = nil
-	cluster_size = nil
-
-	/* Find the optimal map from original histograms to the final ones. */
-	histogramRemapCommand(in, in_size, clusters, num_clusters, out, histogram_symbols)
-
-	clusters = nil
-
-	/* Convert the context map to a canonical form. */
-	*out_size = histogramReindexCommand(out, histogram_symbols, in_size)
-}

compress_fragment.go

@@ -604,7 +604,7 @@ emit_commands:
 				assert(candidate < ip)
 
 				table[hash] = int(ip - base_ip)
-				if !(!isMatch5(in[ip:], in[candidate:])) {
+				if isMatch5(in[ip:], in[candidate:]) {
 					break
 				}
 			}

decode.go

@@ -50,15 +50,6 @@ const (
 	decoderErrorUnreachable                 = -31
 )
 
-/**
- * The value of the last error code, negative integer.
- *
- * All other error code values are in the range from ::lastErrorCode
- * to @c -1. There are also 4 other possible non-error codes @c 0 .. @c 3 in
- * ::BrotliDecoderErrorCode enumeration.
- */
-const lastErrorCode = decoderErrorUnreachable
-
 /** Options to be used with ::BrotliDecoderSetParameter. */
 const (
 	decoderParamDisableRingBufferReallocation = 0
@@ -81,28 +72,6 @@ var kCodeLengthPrefixLength = [16]byte{2, 2, 2, 3, 2, 2, 2, 4, 2, 2, 2, 3, 2, 2,
 
 var kCodeLengthPrefixValue = [16]byte{0, 4, 3, 2, 0, 4, 3, 1, 0, 4, 3, 2, 0, 4, 3, 5}
 
-func decoderSetParameter(state *Reader, p int, value uint32) bool {
-	if state.state != stateUninited {
-		return false
-	}
-	switch p {
-	case decoderParamDisableRingBufferReallocation:
-		if !(value == 0) {
-			state.canny_ringbuffer_allocation = 0
-		} else {
-			state.canny_ringbuffer_allocation = 1
-		}
-		return true
-
-	case decoderParamLargeWindow:
-		state.large_window = (!(value == 0))
-		return true
-
-	default:
-		return false
-	}
-}
-
 /* Saves error code and converts it to BrotliDecoderResult. */
 func saveErrorCode(s *Reader, e int) int {
 	s.error_code = int(e)

http.go

@@ -180,8 +180,8 @@ func init() {
 		var t octetType
 		isCtl := c <= 31 || c == 127
 		isChar := 0 <= c && c <= 127
-		isSeparator := strings.IndexRune(" \t\"(),/:;<=>?@[]\\{}", rune(c)) >= 0
+		isSeparator := strings.ContainsRune(" \t\"(),/:;<=>?@[]\\{}", rune(c))
-		if strings.IndexRune(" \t\r\n", rune(c)) >= 0 {
+		if strings.ContainsRune(" \t\r\n", rune(c)) {
 			t |= isSpace
 		}
 		if isChar && !isCtl && !isSeparator {