Use some Go library functions.

bit_reader.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "encoding/binary"
+
 /* Copyright 2013 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.
@@ -112,7 +114,7 @@ func BrotliFillBitWindow(br *BrotliBitReader, n_bits uint32) {
 	if br.bit_pos_ >= 32 {
 		br.val_ >>= 32
 		br.bit_pos_ ^= 32 /* here same as -= 32 because of the if condition */
-		br.val_ |= (uint64(BROTLI_UNALIGNED_LOAD32LE(br.input[br.byte_pos:]))) << 32
+		br.val_ |= (uint64(binary.LittleEndian.Uint32(br.input[br.byte_pos:]))) << 32
 		br.byte_pos += 4
 	}
 }

compress_fragment.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "encoding/binary"
+
 /* Copyright 2015 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.
@@ -47,7 +49,7 @@ package brotli
    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 = (BROTLI_UNALIGNED_LOAD64LE(p) << 24) * uint64(kHashMul32_a)
+	var h uint64 = (binary.LittleEndian.Uint64(p) << 24) * uint64(kHashMul32_a)
 	return uint32(h >> shift)
 }
 
@@ -695,7 +697,7 @@ emit_commands:
 				   compression we first update "table" with the hashes of some positions
 				   within the last copy. */
 				{
-					var input_bytes uint64 = BROTLI_UNALIGNED_LOAD64LE(in[ip-3:])
+					var input_bytes uint64 = binary.LittleEndian.Uint64(in[ip-3:])
 					var prev_hash uint32 = HashBytesAtOffset5(input_bytes, 0, shift)
 					var cur_hash uint32 = HashBytesAtOffset5(input_bytes, 3, shift)
 					table[prev_hash] = int(ip - base_ip - 3)
@@ -732,7 +734,7 @@ emit_commands:
 				   compression we first update "table" with the hashes of some positions
 				   within the last copy. */
 				{
-					var input_bytes uint64 = BROTLI_UNALIGNED_LOAD64LE(in[ip-3:])
+					var input_bytes uint64 = binary.LittleEndian.Uint64(in[ip-3:])
 					var prev_hash uint32 = HashBytesAtOffset5(input_bytes, 0, shift)
 					var cur_hash uint32 = HashBytesAtOffset5(input_bytes, 3, shift)
 					table[prev_hash] = int(ip - base_ip - 3)

compress_fragment_two_pass.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "encoding/binary"
+
 /* Copyright 2015 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.
@@ -25,7 +27,7 @@ package brotli
 var kCompressFragmentTwoPassBlockSize uint = 1 << 17
 
 func Hash1(p []byte, shift uint, length uint) uint32 {
-	var h uint64 = (BROTLI_UNALIGNED_LOAD64LE(p) << ((8 - length) * 8)) * uint64(kHashMul32_a)
+	var h uint64 = (binary.LittleEndian.Uint64(p) << ((8 - length) * 8)) * uint64(kHashMul32_a)
 	return uint32(h >> shift)
 }
 
@@ -349,7 +351,7 @@ func CreateCommands(input []byte, block_size uint, input_size uint, base_ip_ptr
 
 					var prev_hash uint32
 					if min_match == 4 {
-						input_bytes = BROTLI_UNALIGNED_LOAD64LE(input[ip-3:])
+						input_bytes = binary.LittleEndian.Uint64(input[ip-3:])
 						cur_hash = HashBytesAtOffset(input_bytes, 3, shift, min_match)
 						prev_hash = HashBytesAtOffset(input_bytes, 0, shift, min_match)
 						table[prev_hash] = int(ip - base_ip - 3)
@@ -358,14 +360,14 @@ func CreateCommands(input []byte, block_size uint, input_size uint, base_ip_ptr
 						prev_hash = HashBytesAtOffset(input_bytes, 0, shift, min_match)
 						table[prev_hash] = int(ip - base_ip - 1)
 					} else {
-						input_bytes = BROTLI_UNALIGNED_LOAD64LE(input[ip-5:])
+						input_bytes = binary.LittleEndian.Uint64(input[ip-5:])
 						prev_hash = HashBytesAtOffset(input_bytes, 0, shift, min_match)
 						table[prev_hash] = int(ip - base_ip - 5)
 						prev_hash = HashBytesAtOffset(input_bytes, 1, shift, min_match)
 						table[prev_hash] = int(ip - base_ip - 4)
 						prev_hash = HashBytesAtOffset(input_bytes, 2, shift, min_match)
 						table[prev_hash] = int(ip - base_ip - 3)
-						input_bytes = BROTLI_UNALIGNED_LOAD64LE(input[ip-2:])
+						input_bytes = binary.LittleEndian.Uint64(input[ip-2:])
 						cur_hash = HashBytesAtOffset(input_bytes, 2, shift, min_match)
 						prev_hash = HashBytesAtOffset(input_bytes, 0, shift, min_match)
 						table[prev_hash] = int(ip - base_ip - 2)
@@ -402,7 +404,7 @@ func CreateCommands(input []byte, block_size uint, input_size uint, base_ip_ptr
 
 					var prev_hash uint32
 					if min_match == 4 {
-						input_bytes = BROTLI_UNALIGNED_LOAD64LE(input[ip-3:])
+						input_bytes = binary.LittleEndian.Uint64(input[ip-3:])
 						cur_hash = HashBytesAtOffset(input_bytes, 3, shift, min_match)
 						prev_hash = HashBytesAtOffset(input_bytes, 0, shift, min_match)
 						table[prev_hash] = int(ip - base_ip - 3)
@@ -411,14 +413,14 @@ func CreateCommands(input []byte, block_size uint, input_size uint, base_ip_ptr
 						prev_hash = HashBytesAtOffset(input_bytes, 2, shift, min_match)
 						table[prev_hash] = int(ip - base_ip - 1)
 					} else {
-						input_bytes = BROTLI_UNALIGNED_LOAD64LE(input[ip-5:])
+						input_bytes = binary.LittleEndian.Uint64(input[ip-5:])
 						prev_hash = HashBytesAtOffset(input_bytes, 0, shift, min_match)
 						table[prev_hash] = int(ip - base_ip - 5)
 						prev_hash = HashBytesAtOffset(input_bytes, 1, shift, min_match)
 						table[prev_hash] = int(ip - base_ip - 4)
 						prev_hash = HashBytesAtOffset(input_bytes, 2, shift, min_match)
 						table[prev_hash] = int(ip - base_ip - 3)
-						input_bytes = BROTLI_UNALIGNED_LOAD64LE(input[ip-2:])
+						input_bytes = binary.LittleEndian.Uint64(input[ip-2:])
 						cur_hash = HashBytesAtOffset(input_bytes, 2, shift, min_match)
 						prev_hash = HashBytesAtOffset(input_bytes, 0, shift, min_match)
 						table[prev_hash] = int(ip - base_ip - 2)

fast_log.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "math"
+
 /* Copyright 2013 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.
@@ -311,5 +313,5 @@ func FastLog2(v uint) float64 {
 		return float64(kLog2Table[v])
 	}
 
-	return log2(float64(v))
+	return math.Log2(float64(v))
 }

h10.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "encoding/binary"
+
 /* NOLINT(build/header_guard) */
 /* Copyright 2016 Google Inc. All Rights Reserved.
 
@@ -22,7 +24,7 @@ func (*H10) StoreLookahead() uint {
 }
 
 func HashBytesH10(data []byte) uint32 {
-	var h uint32 = BROTLI_UNALIGNED_LOAD32LE(data) * kHashMul32
+	var h uint32 = binary.LittleEndian.Uint32(data) * kHashMul32
 
 	/* The higher bits contain more mixture from the multiplication,
 	   so we take our results from there. */

h2.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "encoding/binary"
+
 /* NOLINT(build/header_guard) */
 /* Copyright 2010 Google Inc. All Rights Reserved.
 
@@ -22,7 +24,7 @@ func (*H2) StoreLookahead() uint {
    the address in. The HashLongestMatch and H2
    classes have separate, different implementations of hashing. */
 func HashBytesH2(data []byte) uint32 {
-	var h uint64 = ((BROTLI_UNALIGNED_LOAD64LE(data) << (64 - 8*5)) * kHashMul64)
+	var h uint64 = ((binary.LittleEndian.Uint64(data) << (64 - 8*5)) * kHashMul64)
 
 	/* The higher bits contain more mixture from the multiplication,
 	   so we take our results from there. */

h3.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "encoding/binary"
+
 /* NOLINT(build/header_guard) */
 /* Copyright 2010 Google Inc. All Rights Reserved.
 
@@ -18,7 +20,7 @@ func (*H3) StoreLookahead() uint {
    the address in. The HashLongestMatch and H3
    classes have separate, different implementations of hashing. */
 func HashBytesH3(data []byte) uint32 {
-	var h uint64 = ((BROTLI_UNALIGNED_LOAD64LE(data) << (64 - 8*5)) * kHashMul64)
+	var h uint64 = ((binary.LittleEndian.Uint64(data) << (64 - 8*5)) * kHashMul64)
 
 	/* The higher bits contain more mixture from the multiplication,
 	   so we take our results from there. */

h4.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "encoding/binary"
+
 /* NOLINT(build/header_guard) */
 /* Copyright 2010 Google Inc. All Rights Reserved.
 
@@ -18,7 +20,7 @@ func (*H4) StoreLookahead() uint {
    the address in. The HashLongestMatch and H4
    classes have separate, different implementations of hashing. */
 func HashBytesH4(data []byte) uint32 {
-	var h uint64 = ((BROTLI_UNALIGNED_LOAD64LE(data) << (64 - 8*5)) * kHashMul64)
+	var h uint64 = ((binary.LittleEndian.Uint64(data) << (64 - 8*5)) * kHashMul64)
 
 	/* The higher bits contain more mixture from the multiplication,
 	   so we take our results from there. */

h40.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "encoding/binary"
+
 /* NOLINT(build/header_guard) */
 /* Copyright 2016 Google Inc. All Rights Reserved.
 
@@ -23,7 +25,7 @@ func (*H40) StoreLookahead() uint {
 
 /* HashBytes is the function that chooses the bucket to place the address in.*/
 func HashBytesH40(data []byte) uint {
-	var h uint32 = BROTLI_UNALIGNED_LOAD32LE(data) * kHashMul32
+	var h uint32 = binary.LittleEndian.Uint32(data) * kHashMul32
 
 	/* The higher bits contain more mixture from the multiplication,
 	   so we take our results from there. */

h41.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "encoding/binary"
+
 /* NOLINT(build/header_guard) */
 /* Copyright 2016 Google Inc. All Rights Reserved.
 
@@ -23,7 +25,7 @@ func (*H41) StoreLookahead() uint {
 
 /* HashBytes is the function that chooses the bucket to place the address in.*/
 func HashBytesH41(data []byte) uint {
-	var h uint32 = BROTLI_UNALIGNED_LOAD32LE(data) * kHashMul32
+	var h uint32 = binary.LittleEndian.Uint32(data) * kHashMul32
 
 	/* The higher bits contain more mixture from the multiplication,
 	   so we take our results from there. */

h42.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "encoding/binary"
+
 /* NOLINT(build/header_guard) */
 /* Copyright 2016 Google Inc. All Rights Reserved.
 
@@ -23,7 +25,7 @@ func (*H42) StoreLookahead() uint {
 
 /* HashBytes is the function that chooses the bucket to place the address in.*/
 func HashBytesH42(data []byte) uint {
-	var h uint32 = BROTLI_UNALIGNED_LOAD32LE(data) * kHashMul32
+	var h uint32 = binary.LittleEndian.Uint32(data) * kHashMul32
 
 	/* The higher bits contain more mixture from the multiplication,
 	   so we take our results from there. */

h5.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "encoding/binary"
+
 /* NOLINT(build/header_guard) */
 /* Copyright 2010 Google Inc. All Rights Reserved.
 
@@ -23,7 +25,7 @@ func (*H5) StoreLookahead() uint {
 
 /* HashBytes is the function that chooses the bucket to place the address in. */
 func HashBytesH5(data []byte, shift int) uint32 {
-	var h uint32 = BROTLI_UNALIGNED_LOAD32LE(data) * kHashMul32
+	var h uint32 = binary.LittleEndian.Uint32(data) * kHashMul32
 
 	/* The higher bits contain more mixture from the multiplication,
 	   so we take our results from there. */

h54.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "encoding/binary"
+
 /* NOLINT(build/header_guard) */
 /* Copyright 2010 Google Inc. All Rights Reserved.
 
@@ -18,7 +20,7 @@ func (*H54) StoreLookahead() uint {
    the address in. The HashLongestMatch and H54
    classes have separate, different implementations of hashing. */
 func HashBytesH54(data []byte) uint32 {
-	var h uint64 = ((BROTLI_UNALIGNED_LOAD64LE(data) << (64 - 8*7)) * kHashMul64)
+	var h uint64 = ((binary.LittleEndian.Uint64(data) << (64 - 8*7)) * kHashMul64)
 
 	/* The higher bits contain more mixture from the multiplication,
 	   so we take our results from there. */

h6.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "encoding/binary"
+
 /* NOLINT(build/header_guard) */
 /* Copyright 2010 Google Inc. All Rights Reserved.
 
@@ -23,7 +25,7 @@ func (*H6) StoreLookahead() uint {
 
 /* HashBytes is the function that chooses the bucket to place the address in. */
 func HashBytesH6(data []byte, mask uint64, shift int) uint32 {
-	var h uint64 = (BROTLI_UNALIGNED_LOAD64LE(data) & mask) * kHashMul64Long
+	var h uint64 = (binary.LittleEndian.Uint64(data) & mask) * kHashMul64Long
 
 	/* The higher bits contain more mixture from the multiplication,
 	   so we take our results from there. */

hash.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "encoding/binary"
+
 /* Matches data against static dictionary words, and for each length l,
    for which a match is found, updates matches[l] to be the minimum possible
      (distance << 5) + len_code.
@@ -70,7 +72,7 @@ var kHashMul64 uint64 = 0x1E35A7BD1E35A7BD
 var kHashMul64Long uint64 = 0x1FE35A7BD3579BD3
 
 func Hash14(data []byte) uint32 {
-	var h uint32 = BROTLI_UNALIGNED_LOAD32LE(data) * kHashMul32
+	var h uint32 = binary.LittleEndian.Uint32(data) * kHashMul32
 
 	/* The higher bits contain more mixture from the multiplication,
 	   so we take our results from there. */

histogram.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "math"
+
 /* The distance symbols effectively used by "Large Window Brotli" (32-bit). */
 const BROTLI_NUM_HISTOGRAM_DISTANCE_SYMBOLS = 544
 
@@ -12,7 +14,7 @@ type HistogramLiteral struct {
 func HistogramClearLiteral(self *HistogramLiteral) {
 	self.data_ = [BROTLI_NUM_LITERAL_SYMBOLS]uint32{}
 	self.total_count_ = 0
-	self.bit_cost_ = HUGE_VAL
+	self.bit_cost_ = math.MaxFloat64
 }
 
 func ClearHistogramsLiteral(array []HistogramLiteral, length uint) {
@@ -61,7 +63,7 @@ type HistogramCommand struct {
 func HistogramClearCommand(self *HistogramCommand) {
 	self.data_ = [BROTLI_NUM_COMMAND_SYMBOLS]uint32{}
 	self.total_count_ = 0
-	self.bit_cost_ = HUGE_VAL
+	self.bit_cost_ = math.MaxFloat64
 }
 
 func ClearHistogramsCommand(array []HistogramCommand, length uint) {
@@ -110,7 +112,7 @@ type HistogramDistance struct {
 func HistogramClearDistance(self *HistogramDistance) {
 	self.data_ = [BROTLI_NUM_DISTANCE_SYMBOLS]uint32{}
 	self.total_count_ = 0
-	self.bit_cost_ = HUGE_VAL
+	self.bit_cost_ = math.MaxFloat64
 }
 
 func ClearHistogramsDistance(array []HistogramDistance, length uint) {

platform.go

@@ -30,46 +30,6 @@ package brotli
 */
 type brotli_reg_t uint64
 
-/* Read / store values byte-wise; hopefully compiler will understand. */
-func BROTLI_UNALIGNED_LOAD16LE(p []byte) uint16 {
-	var in []byte = []byte(p)
-	return uint16(in[0] | in[1]<<8)
-}
-
-func BROTLI_UNALIGNED_LOAD32LE(p []byte) uint32 {
-	var in []byte = []byte(p)
-	var value uint32 = uint32(in[0])
-	value |= uint32(in[1]) << 8
-	value |= uint32(in[2]) << 16
-	value |= uint32(in[3]) << 24
-	return value
-}
-
-func BROTLI_UNALIGNED_LOAD64LE(p []byte) uint64 {
-	var in []byte = []byte(p)
-	var value uint64 = uint64(in[0])
-	value |= uint64(in[1]) << 8
-	value |= uint64(in[2]) << 16
-	value |= uint64(in[3]) << 24
-	value |= uint64(in[4]) << 32
-	value |= uint64(in[5]) << 40
-	value |= uint64(in[6]) << 48
-	value |= uint64(in[7]) << 56
-	return value
-}
-
-func BROTLI_UNALIGNED_STORE64LE(p []byte, v uint64) {
-	var out []byte = []byte(p)
-	out[0] = byte(v)
-	out[1] = byte(v >> 8)
-	out[2] = byte(v >> 16)
-	out[3] = byte(v >> 24)
-	out[4] = byte(v >> 32)
-	out[5] = byte(v >> 40)
-	out[6] = byte(v >> 48)
-	out[7] = byte(v >> 56)
-}
-
 func brotli_min_double(a float64, b float64) float64 {
 	if a < b {
 		return a

static_dict.go

@@ -1,5 +1,7 @@
 package brotli
 
+import "encoding/binary"
+
 /* Copyright 2013 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.
@@ -17,7 +19,7 @@ var kInvalidMatch uint32 = 0xFFFFFFF
    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
 */
 func Hash(data []byte) uint32 {
-	var h uint32 = BROTLI_UNALIGNED_LOAD32LE(data) * kDictHashMul32
+	var h uint32 = binary.LittleEndian.Uint32(data) * kDictHashMul32
 
 	/* The higher bits contain more mixture from the multiplication,
 	   so we take our results from there. */

util.go

@@ -1,15 +1,7 @@
 package brotli
 
-import "math"
-
-const HUGE_VAL = math.MaxFloat64
-
 func assert(cond bool) {
 	if !cond {
 		panic("assertion failure")
 	}
 }
-
-func log2(n float64) float64 {
-	return math.Log2(n)
-}