/*
* Copyright (c) 2002, 2008, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
struct unpacker;
#define INT_MAX_VALUE ((int)0x7FFFFFFF)
#define INT_MIN_VALUE ((int)0x80000000)
#define CODING_SPEC(B, H, S, D) ((B) << 20 | (H) << 8 | (S) << 4 | (D) << 0)
#define CODING_B(x) ((x) >> 20 & 0xF)
#define CODING_H(x) ((x) >> 8 & 0xFFF)
#define CODING_S(x) ((x) >> 4 & 0xF)
#define CODING_D(x) ((x) >> 0 & 0xF)
#define CODING_INIT(B, H, S, D) \
{ \
CODING_SPEC(B, H, S, D), 0, 0, 0, 0, 0, 0, 0, 0 \
}
// For debugging purposes, some compilers do not like this and will complain.
// #define long do_not_use_C_long_types_use_jlong_or_int
// Use of the type "long" is problematic, do not use it.
struct coding
{
int spec; // B,H,S,D
// Handy values derived from the spec:
int B()
{
return CODING_B(spec);
}
int H()
{
return CODING_H(spec);
}
int S()
{
return CODING_S(spec);
}
int D()
{
return CODING_D(spec);
}
int L()
{
return 256 - CODING_H(spec);
}
int min, max;
int umin, umax;
char isSigned, isSubrange, isFullRange, isMalloc;
coding *init(); // returns self or nullptr if error
coding *initFrom(int spec_)
{
assert(this->spec == 0);
this->spec = spec_;
return init();
}
static coding *findBySpec(int spec);
static coding *findBySpec(int B, int H, int S = 0, int D = 0);
static coding *findByIndex(int irregularCodingIndex);
static uint32_t parse(byte *&rp, int B, int H);
static uint32_t parse_lgH(byte *&rp, int B, int H, int lgH);
static void parseMultiple(byte *&rp, int N, byte *limit, int B, int H);
uint32_t parse(byte *&rp)
{
return parse(rp, CODING_B(spec), CODING_H(spec));
}
void parseMultiple(byte *&rp, int N, byte *limit)
{
parseMultiple(rp, N, limit, CODING_B(spec), CODING_H(spec));
}
bool canRepresent(int x)
{
return (x >= min && x <= max);
}
bool canRepresentUnsigned(int x)
{
return (x >= umin && x <= umax);
}
int sumInUnsignedRange(int x, int y);
int readFrom(byte *&rpVar, int *dbase);
void readArrayFrom(byte *&rpVar, int *dbase, int length, int *values);
void skipArrayFrom(byte *&rpVar, int length)
{
readArrayFrom(rpVar, (int *)NULL, length, (int *)NULL);
}
void free(); // free self if isMalloc
};
enum coding_method_kind
{
cmk_ERROR,
cmk_BHS,
cmk_BHS0,
cmk_BHS1,
cmk_BHSD1,
cmk_BHS1D1full, // isFullRange
cmk_BHS1D1sub, // isSubRange
// special cases hand-optimized (~50% of all decoded values)
cmk_BYTE1, //(1,256) 6%
cmk_CHAR3, //(3,128) 7%
cmk_UNSIGNED5, //(5,64) 13%
cmk_DELTA5, //(5,64,1,1) 5%
cmk_BCI5, //(5,4) 18%
cmk_BRANCH5, //(5,4,2) 4%
// cmk_UNSIGNED5H16, //(5,16) 5%
// cmk_UNSIGNED2H4, //(2,4) 6%
// cmk_DELTA4H8, //(4,8,1,1) 10%
// cmk_DELTA3H16, //(3,16,1,1) 9%
cmk_BHS_LIMIT,
cmk_pop,
cmk_pop_BHS0,
cmk_pop_BYTE1,
cmk_pop_LIMIT,
cmk_LIMIT
};
enum
{
BYTE1_spec = CODING_SPEC(1, 256, 0, 0),
CHAR3_spec = CODING_SPEC(3, 128, 0, 0),
UNSIGNED4_spec = CODING_SPEC(4, 256, 0, 0),
UNSIGNED5_spec = CODING_SPEC(5, 64, 0, 0),
SIGNED5_spec = CODING_SPEC(5, 64, 1, 0),
DELTA5_spec = CODING_SPEC(5, 64, 1, 1),
UDELTA5_spec = CODING_SPEC(5, 64, 0, 1),
MDELTA5_spec = CODING_SPEC(5, 64, 2, 1),
BCI5_spec = CODING_SPEC(5, 4, 0, 0),
BRANCH5_spec = CODING_SPEC(5, 4, 2, 0)
};
enum
{
B_MAX = 5,
C_SLOP = B_MAX * 10
};
struct coding_method;
// iterator under the control of a meta-coding
struct value_stream
{
// current coding of values or values
coding c; // B,H,S,D,etc.
coding_method_kind cmk; // type of decoding needed
byte *rp; // read pointer
byte *rplimit; // final value of read pointer
int sum; // partial sum of all values so far (D=1 only)
coding_method *cm; // coding method that defines this stream
void init(byte *band_rp, byte *band_limit, coding *defc);
void init(byte *band_rp, byte *band_limit, int spec)
{
init(band_rp, band_limit, coding::findBySpec(spec));
}
void setCoding(coding *c);
void setCoding(int spec)
{
setCoding(coding::findBySpec(spec));
}
// Parse and decode a single value.
int getInt();
// Parse and decode a single byte, with no error checks.
int getByte()
{
assert(cmk == cmk_BYTE1);
assert(rp < rplimit);
return *rp++ & 0xFF;
}
// Used only for asserts.
bool hasValue();
void done()
{
assert(!hasValue());
}
// Sometimes a value stream has an auxiliary (but there are never two).
value_stream *helper()
{
assert(hasHelper());
return this + 1;
}
bool hasHelper();
};
struct coding_method
{
value_stream vs0; // initial state snapshot (vs.meta==this)
coding_method *next; // what to do when we run out of bytes
// these fields are used for pop codes only:
int *fValues; // favored value array
int fVlength; // maximum favored value token
coding_method *uValues; // unfavored value stream
// pointer to outer unpacker, for error checks etc.
unpacker *u;
// Initialize a value stream.
void reset(value_stream *state);
// Parse a band header, size a band, and initialize for further action.
// band_rp advances (but not past band_limit), and meta_rp advances.
// The mode gives context, such as "inside a pop".
// The defc and N are the incoming parameters to a meta-coding.
// The value sink is used to collect output values, when desired.
void init(byte *&band_rp, byte *band_limit, byte *&meta_rp, int mode, coding *defc, int N,
intlist *valueSink);
};