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Kirill Smelkov
go
Commits
5fca0bca
Commit
5fca0bca
authored
Nov 04, 2009
by
Robert Griesemer
Browse files
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Plain Diff
gofmt-ify compress
R=rsc
http://go/go-review/1016045
parent
b6d0a22d
Changes
3
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Inline
Side-by-side
Showing
3 changed files
with
61 additions
and
56 deletions
+61
-56
src/pkg/compress/flate/huffman_bit_writer.go
src/pkg/compress/flate/huffman_bit_writer.go
+4
-4
src/pkg/compress/flate/huffman_code.go
src/pkg/compress/flate/huffman_code.go
+56
-49
src/pkg/compress/flate/inflate.go
src/pkg/compress/flate/inflate.go
+1
-3
No files found.
src/pkg/compress/flate/huffman_bit_writer.go
View file @
5fca0bca
...
...
@@ -31,10 +31,10 @@ const (
// The number of extra bits needed by length code X - LENGTH_CODES_START.
var
lengthExtraBits
=
[]
int8
{
/* 257 */
0
,
0
,
0
,
/* 260 */
0
,
0
,
0
,
0
,
0
,
1
,
1
,
1
,
1
,
2
,
/* 270 */
2
,
2
,
2
,
3
,
3
,
3
,
3
,
4
,
4
,
4
,
/* 280 */
4
,
5
,
5
,
5
,
5
,
0
,
/* 257 */
0
,
0
,
0
,
/* 260 */
0
,
0
,
0
,
0
,
0
,
1
,
1
,
1
,
1
,
2
,
/* 270 */
2
,
2
,
2
,
3
,
3
,
3
,
3
,
4
,
4
,
4
,
/* 280 */
4
,
5
,
5
,
5
,
5
,
0
,
}
// The length indicated by length code X - LENGTH_CODES_START.
...
...
src/pkg/compress/flate/huffman_code.go
View file @
5fca0bca
...
...
@@ -56,11 +56,11 @@ type levelInfo struct {
}
func
maxNode
()
literalNode
{
return
literalNode
{
math
.
MaxUint16
,
math
.
MaxInt32
};
return
literalNode
{
math
.
MaxUint16
,
math
.
MaxInt32
};
}
func
newHuffmanEncoder
(
size
int
)
*
huffmanEncoder
{
return
&
huffmanEncoder
{
make
([]
uint8
,
size
),
make
([]
uint16
,
size
)
};
return
&
huffmanEncoder
{
make
([]
uint8
,
size
),
make
([]
uint16
,
size
)
};
}
// Generates a HuffmanCode corresponding to the fixed literal table
...
...
@@ -75,16 +75,23 @@ func generateFixedLiteralEncoding() *huffmanEncoder {
switch
{
case
ch
<
144
:
// size 8, 000110000 .. 10111111
bits
=
ch
+
48
;
size
=
8
;
break
;
bits
=
ch
+
48
;
size
=
8
;
break
;
case
ch
<
256
:
// size 9, 110010000 .. 111111111
bits
=
ch
+
400
-
144
;
size
=
9
;
break
;
bits
=
ch
+
400
-
144
;
size
=
9
;
break
;
case
ch
<
280
:
// size 7, 0000000 .. 0010111
bits
=
ch
-
256
;
size
=
7
;
break
;
bits
=
ch
-
256
;
size
=
7
;
break
;
default
:
// size 8, 11000000 .. 11000111
bits
=
ch
+
192
-
280
;
size
=
8
;
bits
=
ch
+
192
-
280
;
size
=
8
;
}
codeBits
[
ch
]
=
size
;
code
[
ch
]
=
reverseBits
(
bits
,
size
);
...
...
@@ -103,14 +110,14 @@ func generateFixedOffsetEncoding() *huffmanEncoder {
return
h
;
}
var
fixedLiteralEncoding
*
huffmanEncoder
=
generateFixedLiteralEncoding
()
;
var
fixedOffsetEncoding
*
huffmanEncoder
=
generateFixedOffsetEncoding
()
;
var
fixedLiteralEncoding
*
huffmanEncoder
=
generateFixedLiteralEncoding
()
var
fixedOffsetEncoding
*
huffmanEncoder
=
generateFixedOffsetEncoding
()
func
(
h
*
huffmanEncoder
)
bitLength
(
freq
[]
int32
)
int64
{
var
total
int64
;
for
i
,
f
:=
range
freq
{
if
f
!=
0
{
total
+=
int64
(
f
)
*
int64
(
h
.
codeBits
[
i
]);
total
+=
int64
(
f
)
*
int64
(
h
.
codeBits
[
i
]);
}
}
return
total
;
...
...
@@ -119,7 +126,7 @@ func (h *huffmanEncoder) bitLength(freq []int32) int64 {
// Generate elements in the chain using an iterative algorithm.
func
(
h
*
huffmanEncoder
)
generateChains
(
top
*
levelInfo
,
list
[]
literalNode
)
{
n
:=
len
(
list
);
list
=
list
[
0
:
n
+
1
];
list
=
list
[
0
:
n
+
1
];
list
[
n
]
=
maxNode
();
l
:=
top
;
...
...
@@ -140,13 +147,13 @@ func (h *huffmanEncoder) generateChains(top *levelInfo, list []literalNode) {
if
l
.
nextCharFreq
<
l
.
nextPairFreq
{
// The next item on this row is a leaf node.
n
:=
l
.
lastChain
.
leafCount
+
1
;
l
.
lastChain
=
&
chain
{
l
.
nextCharFreq
,
n
,
l
.
lastChain
.
up
};
l
.
lastChain
=
&
chain
{
l
.
nextCharFreq
,
n
,
l
.
lastChain
.
up
};
l
.
nextCharFreq
=
list
[
n
]
.
freq
;
}
else
{
// The next item on this row is a pair from the previous row.
// nextPairFreq isn't valid until we generate two
// more values in the level below
l
.
lastChain
=
&
chain
{
l
.
nextPairFreq
,
l
.
lastChain
.
leafCount
,
l
.
down
.
lastChain
};
l
.
lastChain
=
&
chain
{
l
.
nextPairFreq
,
l
.
lastChain
.
leafCount
,
l
.
down
.
lastChain
};
l
.
down
.
needed
=
2
;
}
...
...
@@ -185,19 +192,19 @@ func (h *huffmanEncoder) generateChains(top *levelInfo, list []literalNode) {
// that should be encoded in i bits.
func
(
h
*
huffmanEncoder
)
bitCounts
(
list
[]
literalNode
,
maxBits
int32
)
[]
int32
{
n
:=
int32
(
len
(
list
));
list
=
list
[
0
:
n
+
1
];
list
=
list
[
0
:
n
+
1
];
list
[
n
]
=
maxNode
();
// The tree can't have greater depth than n - 1, no matter what. This
// saves a little bit of work in some small cases
maxBits
=
minInt32
(
maxBits
,
n
-
1
);
maxBits
=
minInt32
(
maxBits
,
n
-
1
);
// Create information about each of the levels.
// A bogus "Level 0" whose sole purpose is so that
// level1.prev.needed==0. This makes level1.nextPairFreq
// be a legitimate value that never gets chosen.
top
:=
&
levelInfo
{
needed
:
0
};
chain2
:=
&
chain
{
list
[
1
]
.
freq
,
2
,
new
(
chain
)
};
chain2
:=
&
chain
{
list
[
1
]
.
freq
,
2
,
new
(
chain
)
};
for
level
:=
int32
(
1
);
level
<=
maxBits
;
level
++
{
// For every level, the first two items are the first two characters.
// We initialize the levels as if we had already figured this out.
...
...
@@ -235,13 +242,13 @@ func (h *huffmanEncoder) bitCounts(list []literalNode, maxBits int32) []int32 {
if
l
.
nextCharFreq
<
l
.
nextPairFreq
{
// The next item on this row is a leaf node.
n
:=
l
.
lastChain
.
leafCount
+
1
;
l
.
lastChain
=
&
chain
{
l
.
nextCharFreq
,
n
,
l
.
lastChain
.
up
};
l
.
lastChain
=
&
chain
{
l
.
nextCharFreq
,
n
,
l
.
lastChain
.
up
};
l
.
nextCharFreq
=
list
[
n
]
.
freq
;
}
else
{
// The next item on this row is a pair from the previous row.
// nextPairFreq isn't valid until we generate two
// more values in the level below
l
.
lastChain
=
&
chain
{
l
.
nextPairFreq
,
l
.
lastChain
.
leafCount
,
l
.
down
.
lastChain
};
l
.
lastChain
=
&
chain
{
l
.
nextPairFreq
,
l
.
lastChain
.
leafCount
,
l
.
down
.
lastChain
};
l
.
down
.
needed
=
2
;
}
...
...
@@ -272,7 +279,7 @@ func (h *huffmanEncoder) bitCounts(list []literalNode, maxBits int32) []int32 {
panic
(
"top.lastChain.leafCount != n"
);
}
bitCount
:=
make
([]
int32
,
maxBits
+
1
);
bitCount
:=
make
([]
int32
,
maxBits
+
1
);
bits
:=
1
;
for
chain
:=
top
.
lastChain
;
chain
.
up
!=
nil
;
chain
=
chain
.
up
{
// chain.leafCount gives the number of literals requiring at least "bits"
...
...
@@ -296,14 +303,14 @@ func (h *huffmanEncoder) assignEncodingAndSize(bitCount []int32, list []literalN
// are encoded using "bits" bits, and get the values
// code, code + 1, .... The code values are
// assigned in literal order (not frequency order).
chunk
:=
list
[
len
(
list
)
-
int
(
bits
)
:
len
(
list
)];
chunk
:=
list
[
len
(
list
)
-
int
(
bits
)
:
len
(
list
)];
sortByLiteral
(
chunk
);
for
_
,
node
:=
range
chunk
{
h
.
codeBits
[
node
.
literal
]
=
uint8
(
n
);
h
.
code
[
node
.
literal
]
=
reverseBits
(
code
,
uint8
(
n
));
code
++
;
}
list
=
list
[
0
:
len
(
list
)
-
int
(
bits
)];
list
=
list
[
0
:
len
(
list
)
-
int
(
bits
)];
}
}
...
...
@@ -312,7 +319,7 @@ func (h *huffmanEncoder) assignEncodingAndSize(bitCount []int32, list []literalN
// freq An array of frequencies, in which frequency[i] gives the frequency of literal i.
// maxBits The maximum number of bits to use for any literal.
func
(
h
*
huffmanEncoder
)
generate
(
freq
[]
int32
,
maxBits
int32
)
{
list
:=
make
([]
literalNode
,
len
(
freq
)
+
1
);
list
:=
make
([]
literalNode
,
len
(
freq
)
+
1
);
// Number of non-zero literals
count
:=
0
;
// Set list to be the set of all non-zero literals and their frequencies
...
...
@@ -347,7 +354,7 @@ func (h *huffmanEncoder) generate(freq []int32, maxBits int32) {
type
literalNodeSorter
struct
{
a
[]
literalNode
;
less
func
(
i
,
j
int
)
bool
;
less
func
(
i
,
j
int
)
bool
;
}
func
(
s
literalNodeSorter
)
Len
()
int
{
...
...
@@ -358,16 +365,16 @@ func (s literalNodeSorter) Less(i, j int) bool {
return
s
.
less
(
i
,
j
);
}
func
(
s
literalNodeSorter
)
Swap
(
i
,
j
int
)
{
func
(
s
literalNodeSorter
)
Swap
(
i
,
j
int
)
{
s
.
a
[
i
],
s
.
a
[
j
]
=
s
.
a
[
j
],
s
.
a
[
i
];
}
func
sortByFreq
(
a
[]
literalNode
)
{
s
:=
&
literalNodeSorter
{
a
,
func
(
i
,
j
int
)
bool
{
return
a
[
i
]
.
freq
<
a
[
j
]
.
freq
;
}};
s
:=
&
literalNodeSorter
{
a
,
func
(
i
,
j
int
)
bool
{
return
a
[
i
]
.
freq
<
a
[
j
]
.
freq
}};
sort
.
Sort
(
s
);
}
func
sortByLiteral
(
a
[]
literalNode
)
{
s
:=
&
literalNodeSorter
{
a
,
func
(
i
,
j
int
)
bool
{
return
a
[
i
]
.
literal
<
a
[
j
]
.
literal
;
}};
s
:=
&
literalNodeSorter
{
a
,
func
(
i
,
j
int
)
bool
{
return
a
[
i
]
.
literal
<
a
[
j
]
.
literal
}};
sort
.
Sort
(
s
);
}
src/pkg/compress/flate/inflate.go
View file @
5fca0bca
...
...
@@ -609,8 +609,6 @@ func (f *inflater) inflater(r io.Reader, w io.Writer) os.Error {
func
NewInflater
(
r
io
.
Reader
)
io
.
ReadCloser
{
var
f
inflater
;
pr
,
pw
:=
io
.
Pipe
();
go
func
()
{
pw
.
CloseWithError
(
f
.
inflater
(
r
,
pw
));
}();
go
func
()
{
pw
.
CloseWithError
(
f
.
inflater
(
r
,
pw
))
}();
return
pr
;
}
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