Clean up duplicate and misplaced comments.

backward_references.go

@@ -6,19 +6,8 @@ package brotli
    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
 */
 
-/* Function to find backward reference copies. */
-/* Copyright 2013 Google Inc. All Rights Reserved.
-
-   Distributed under MIT license.
-   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
-*/
-
 /* Function to find backward reference copies. */
 
-/* "commands" points to the next output command to write to, "*num_commands" is
-   initially the total amount of commands output by previous
-   CreateBackwardReferences calls, and must be incremented by the amount written
-   by this call. */
 func computeDistanceCode(distance uint, max_distance uint, dist_cache []int) uint {
 	if distance <= max_distance {
 		var distance_plus_3 uint = distance + 3
@@ -42,6 +31,10 @@ func computeDistanceCode(distance uint, max_distance uint, dist_cache []int) uin
 	return distance + numDistanceShortCodes - 1
 }
 
+/* "commands" points to the next output command to write to, "*num_commands" is
+   initially the total amount of commands output by previous
+   CreateBackwardReferences calls, and must be incremented by the amount written
+   by this call. */
 func createBackwardReferences(num_bytes uint, position uint, ringbuffer []byte, ringbuffer_mask uint, params *encoderParams, hasher hasherHandle, dist_cache []int, last_insert_len *uint, commands []command, num_commands *uint, num_literals *uint) {
 	var max_backward_limit uint = maxBackwardLimit(params.lgwin)
 	var orig_commands []command = commands

backward_references_hq.go

@@ -13,19 +13,6 @@ type zopfliNode struct {
 	}
 }
 
-/* Computes the shortest path of commands from position to at most
-   position + num_bytes.
-
-   On return, path->size() is the number of commands found and path[i] is the
-   length of the i-th command (copy length plus insert length).
-   Note that the sum of the lengths of all commands can be less than num_bytes.
-
-   On return, the nodes[0..num_bytes] array will have the following
-   "ZopfliNode array invariant":
-   For each i in [1..num_bytes], if nodes[i].cost < kInfinity, then
-     (1) nodes[i].copy_length() >= 2
-     (2) nodes[i].command_length() <= i and
-     (3) nodes[i - nodes[i].command_length()].cost < kInfinity */
 const maxEffectiveDistanceAlphabetSize = 544
 
 var kInfinity float32 = 1.7e38 /* ~= 2 ^ 127 */
@@ -618,7 +605,21 @@ func zopfliIterate(num_bytes uint, position uint, ringbuffer []byte, ringbuffer_
 	return computeShortestPathFromNodes(num_bytes, nodes)
 }
 
-/* REQUIRES: nodes != NULL and len(nodes) >= num_bytes + 1 */
+/* Computes the shortest path of commands from position to at most
+   position + num_bytes.
+
+   On return, path->size() is the number of commands found and path[i] is the
+   length of the i-th command (copy length plus insert length).
+   Note that the sum of the lengths of all commands can be less than num_bytes.
+
+   On return, the nodes[0..num_bytes] array will have the following
+   "ZopfliNode array invariant":
+   For each i in [1..num_bytes], if nodes[i].cost < kInfinity, then
+     (1) nodes[i].copy_length() >= 2
+     (2) nodes[i].command_length() <= i and
+     (3) nodes[i - nodes[i].command_length()].cost < kInfinity
+
+ REQUIRES: nodes != nil and len(nodes) >= num_bytes + 1 */
 func zopfliComputeShortestPath(num_bytes uint, position uint, ringbuffer []byte, ringbuffer_mask uint, params *encoderParams, dist_cache []int, hasher *h10, nodes []zopfliNode) uint {
 	var max_backward_limit uint = maxBackwardLimit(params.lgwin)
 	var max_zopfli_len uint = maxZopfliLen(params)

bit_cost.go

@@ -6,13 +6,6 @@ package brotli
    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
 */
 
-/* Functions to estimate the bit cost of Huffman trees. */
-/* Copyright 2013 Google Inc. All Rights Reserved.
-
-   Distributed under MIT license.
-   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
-*/
-
 /* Functions to estimate the bit cost of Huffman trees. */
 func shannonEntropy(population []uint32, size uint, total *uint) float64 {
 	var sum uint = 0

bit_reader.go

@@ -9,6 +9,7 @@ import "encoding/binary"
 */
 
 /* Bit reading helpers */
+
 const shortFillBitWindowRead = (8 >> 1)
 
 var kBitMask = [33]uint32{

block_splitter.go

@@ -6,21 +6,8 @@ package brotli
    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
 */
 
-/* Build per-context histograms of literals, commands and distance codes. */
-/* Copyright 2013 Google Inc. All Rights Reserved.
-
-   Distributed under MIT license.
-   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
-*/
-
-/* Models the histograms of literals, commands and distance codes. */
-/* Copyright 2013 Google Inc. All Rights Reserved.
-
-   Distributed under MIT license.
-   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
-*/
-
 /* Block split point selection utilities. */
+
 type blockSplit struct {
 	num_types          uint
 	num_blocks         uint

block_splitter_command.go

@@ -2,12 +2,12 @@ package brotli
 
 import "math"
 
-/* NOLINT(build/header_guard) */
 /* Copyright 2013 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.
    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
 */
+
 func initialEntropyCodesCommand(data []uint16, length uint, stride uint, num_histograms uint, histograms []histogramCommand) {
 	var seed uint32 = 7
 	var block_length uint = length / num_histograms

block_splitter_distance.go

@@ -2,12 +2,12 @@ package brotli
 
 import "math"
 
-/* NOLINT(build/header_guard) */
 /* Copyright 2013 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.
    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
 */
+
 func initialEntropyCodesDistance(data []uint16, length uint, stride uint, num_histograms uint, histograms []histogramDistance) {
 	var seed uint32 = 7
 	var block_length uint = length / num_histograms

block_splitter_literal.go

@@ -2,12 +2,12 @@ package brotli
 
 import "math"
 
-/* NOLINT(build/header_guard) */
 /* Copyright 2013 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.
    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
 */
+
 func initialEntropyCodesLiteral(data []byte, length uint, stride uint, num_histograms uint, histograms []histogramLiteral) {
 	var seed uint32 = 7
 	var block_length uint = length / num_histograms

cluster.go

@@ -6,28 +6,15 @@ package brotli
    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
 */
 
-/* Block split point selection utilities. */
-/* Copyright 2013 Google Inc. All Rights Reserved.
-
-   Distributed under MIT license.
-   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
-*/
-
 /* Functions for clustering similar histograms together. */
+
 type histogramPair struct {
 	idx1       uint32
 	idx2       uint32
 	cost_combo float64
 	cost_diff  float64
 }
 
-/* Copyright 2013 Google Inc. All Rights Reserved.
-
-   Distributed under MIT license.
-   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
-*/
-
-/* Functions for clustering similar histograms together. */
 func histogramPairIsLess(p1 *histogramPair, p2 *histogramPair) bool {
 	if p1.cost_diff != p2.cost_diff {
 		return p1.cost_diff > p2.cost_diff

cluster_command.go

@@ -2,7 +2,6 @@ package brotli
 
 import "math"
 
-/* NOLINT(build/header_guard) */
 /* Copyright 2013 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.

cluster_distance.go

@@ -2,7 +2,6 @@ package brotli
 
 import "math"
 
-/* NOLINT(build/header_guard) */
 /* Copyright 2013 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.

cluster_literal.go

@@ -2,7 +2,6 @@ package brotli
 
 import "math"
 
-/* NOLINT(build/header_guard) */
 /* Copyright 2013 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.

compress_fragment.go

@@ -15,49 +15,19 @@ import "encoding/binary"
 
    Adapted from the CompressFragment() function in
    https://github.com/google/snappy/blob/master/snappy.cc */
-/* Copyright 2015 Google Inc. All Rights Reserved.
-
-   Distributed under MIT license.
-   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
-*/
-
-/* Function for fast encoding of an input fragment, independently from the input
-   history. This function uses one-pass processing: when we find a backward
-   match, we immediately emit the corresponding command and literal codes to
-   the bit stream. */
-
-/* Compresses "input" string to the "*storage" buffer as one or more complete
-   meta-blocks, and updates the "*storage_ix" bit position.
-
-   If "is_last" is 1, emits an additional empty last meta-block.
 
-   "cmd_depth" and "cmd_bits" contain the command and distance prefix codes
-   (see comment in encode.h) used for the encoding of this input fragment.
-   If "is_last" is 0, they are updated to reflect the statistics
-   of this input fragment, to be used for the encoding of the next fragment.
+const maxDistance_compress_fragment = 262128
 
-   "*cmd_code_numbits" is the number of bits of the compressed representation
-   of the command and distance prefix codes, and "cmd_code" is an array of
-   at least "(*cmd_code_numbits + 7) >> 3" size that contains the compressed
-   command and distance prefix codes. If "is_last" is 0, these are also
-   updated to represent the updated "cmd_depth" and "cmd_bits".
-
-   REQUIRES: "input_size" is greater than zero, or "is_last" is 1.
-   REQUIRES: "input_size" is less or equal to maximal metablock size (1 << 24).
-   REQUIRES: All elements in "table[0..table_size-1]" are initialized to zero.
-   REQUIRES: "table_size" is an odd (9, 11, 13, 15) power of two
-   OUTPUT: maximal copy distance <= |input_size|
-   OUTPUT: maximal copy distance <= BROTLI_MAX_BACKWARD_LIMIT(18) */
 func hash5(p []byte, shift uint) uint32 {
-	var h uint64 = (binary.LittleEndian.Uint64(p) << 24) * uint64(kHashMul32_a)
+	var h uint64 = (binary.LittleEndian.Uint64(p) << 24) * uint64(kHashMul32)
 	return uint32(h >> shift)
 }
 
 func hashBytesAtOffset5(v uint64, offset int, shift uint) uint32 {
 	assert(offset >= 0)
 	assert(offset <= 3)
 	{
-		var h uint64 = ((v >> uint(8*offset)) << 24) * uint64(kHashMul32_a)
+		var h uint64 = ((v >> uint(8*offset)) << 24) * uint64(kHashMul32)
 		return uint32(h >> shift)
 	}
 }
@@ -821,6 +791,28 @@ next_block:
 	}
 }
 
+/* Compresses "input" string to the "*storage" buffer as one or more complete
+   meta-blocks, and updates the "*storage_ix" bit position.
+
+   If "is_last" is 1, emits an additional empty last meta-block.
+
+   "cmd_depth" and "cmd_bits" contain the command and distance prefix codes
+   (see comment in encode.h) used for the encoding of this input fragment.
+   If "is_last" is 0, they are updated to reflect the statistics
+   of this input fragment, to be used for the encoding of the next fragment.
+
+   "*cmd_code_numbits" is the number of bits of the compressed representation
+   of the command and distance prefix codes, and "cmd_code" is an array of
+   at least "(*cmd_code_numbits + 7) >> 3" size that contains the compressed
+   command and distance prefix codes. If "is_last" is 0, these are also
+   updated to represent the updated "cmd_depth" and "cmd_bits".
+
+   REQUIRES: "input_size" is greater than zero, or "is_last" is 1.
+   REQUIRES: "input_size" is less or equal to maximal metablock size (1 << 24).
+   REQUIRES: All elements in "table[0..table_size-1]" are initialized to zero.
+   REQUIRES: "table_size" is an odd (9, 11, 13, 15) power of two
+   OUTPUT: maximal copy distance <= |input_size|
+   OUTPUT: maximal copy distance <= BROTLI_MAX_BACKWARD_LIMIT(18) */
 func compressFragmentFast(input []byte, input_size uint, is_last bool, table []int, table_size uint, cmd_depth []byte, cmd_bits []uint16, cmd_code_numbits *uint, cmd_code []byte, storage_ix *uint, storage []byte) {
 	var initial_storage_ix uint = *storage_ix
 	var table_bits uint = uint(log2FloorNonZero(table_size))

compress_fragment_two_pass.go

@@ -13,28 +13,18 @@ import "encoding/binary"
    the found backward matches and literal bytes into a buffer, and in the
    second pass we emit them into the bit stream using prefix codes built based
    on the actual command and literal byte histograms. */
-/* Copyright 2015 Google Inc. All Rights Reserved.
-
-   Distributed under MIT license.
-   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
-*/
 
-/* Function for fast encoding of an input fragment, independently from the input
-   history. This function uses two-pass processing: in the first pass we save
-   the found backward matches and literal bytes into a buffer, and in the
-   second pass we emit them into the bit stream using prefix codes built based
-   on the actual command and literal byte histograms. */
 var kCompressFragmentTwoPassBlockSize uint = 1 << 17
 
 func hash1(p []byte, shift uint, length uint) uint32 {
-	var h uint64 = (binary.LittleEndian.Uint64(p) << ((8 - length) * 8)) * uint64(kHashMul32_a)
+	var h uint64 = (binary.LittleEndian.Uint64(p) << ((8 - length) * 8)) * uint64(kHashMul32)
 	return uint32(h >> shift)
 }
 
 func hashBytesAtOffset(v uint64, offset uint, shift uint, length uint) uint32 {
 	assert(offset <= 8-length)
 	{
-		var h uint64 = ((v >> (8 * offset)) << ((8 - length) * 8)) * uint64(kHashMul32_a)
+		var h uint64 = ((v >> (8 * offset)) << ((8 - length) * 8)) * uint64(kHashMul32)
 		return uint32(h >> shift)
 	}
 }
@@ -721,6 +711,19 @@ func compressFragmentTwoPassImpl(input []byte, input_size uint, is_last bool, co
 	}
 }
 
+/* Compresses "input" string to the "*storage" buffer as one or more complete
+   meta-blocks, and updates the "*storage_ix" bit position.
+
+   If "is_last" is 1, emits an additional empty last meta-block.
+
+   REQUIRES: "input_size" is greater than zero, or "is_last" is 1.
+   REQUIRES: "input_size" is less or equal to maximal metablock size (1 << 24).
+   REQUIRES: "command_buf" and "literal_buf" point to at least
+              kCompressFragmentTwoPassBlockSize long arrays.
+   REQUIRES: All elements in "table[0..table_size-1]" are initialized to zero.
+   REQUIRES: "table_size" is a power of two
+   OUTPUT: maximal copy distance <= |input_size|
+   OUTPUT: maximal copy distance <= BROTLI_MAX_BACKWARD_LIMIT(18) */
 func compressFragmentTwoPass(input []byte, input_size uint, is_last bool, command_buf []uint32, literal_buf []byte, table []int, table_size uint, storage_ix *uint, storage []byte) {
 	var initial_storage_ix uint = *storage_ix
 	var table_bits uint = uint(log2FloorNonZero(table_size))