mirror of
https://github.com/Alcaro/Flips.git
synced 2026-09-02 16:04:36 -05:00
Initial commit - version 1.31
This commit is contained in:
Alcaro
891
libbps-suf.cpp
Normal file
891
libbps-suf.cpp
Normal file
@@ -0,0 +1,891 @@
|
||||
//Module name: libbps-suf
|
||||
//Author: Alcaro
|
||||
//Date: June 18, 2015
|
||||
//Licence: GPL v3.0 or higher
|
||||
|
||||
|
||||
#include "libbps.h"
|
||||
#include "crc32.h"
|
||||
#include <stdint.h>
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
#include <stdio.h>
|
||||
|
||||
//These two give minor performance penalties and will print some random stuff to stdout.
|
||||
//The former will verify the correctness of the output patch, the latter will print some performance data.
|
||||
//Can be useful for debugging, but should be disabled for release builds.
|
||||
#ifdef BPS_STANDALONE
|
||||
#endif
|
||||
//#define TEST_CORRECT
|
||||
//#define TEST_PERF
|
||||
|
||||
//If the suffix array of [0, 0, 0, 0] is [3, 2, 1, 0], set to true. If it's [0, 1, 2, 3], this is false.
|
||||
//If it's [4, 3, 2, 1, 0] or [0, 1, 2, 3, 4], remove the 4 (easily done with some pointer math), and follow the above.
|
||||
//If it's something else, get a non-broken array calculator.
|
||||
#define EOF_IS_LAST false
|
||||
|
||||
#if defined(TEST_CORRECT) || defined(TEST_PERF)
|
||||
#include <stdio.h>
|
||||
#endif
|
||||
|
||||
//Algorithm description:
|
||||
//
|
||||
//This is heavily built upon suffix sorting; the implementation I use, libdivsufsort, claims
|
||||
// O(n log n) complexity, so I'll believe that. There is also SA-IS, which claims O(n), but if that
|
||||
// is true, its constant factors are ridiculously high.
|
||||
//
|
||||
//The program starts by taking an equal amount of the source file and target file, concatenates that
|
||||
// with target first, and suffix sorts it.
|
||||
//It also calculates a reverse index, such that reverse[sorted[i]]==i.
|
||||
//
|
||||
//To find a match, it goes to reverse[outpos], and scans sorted[] up and down for the closest entry
|
||||
// that either starts before the current output position, or is somewhere in the source file.
|
||||
//As the source file comes last, the end-of-file marker (whose value is outside the range of a byte)
|
||||
// is guaranteed to not be in the way for a better match.
|
||||
//This is called O(n) times, and averages O(1) as at least 50% of sorted[] is in range. However, it
|
||||
// is worst-case O(n) for sorted inputs, giving a total of O(n^2).
|
||||
//
|
||||
//It then checks which of the two candidates are superior, by checking how far they match each
|
||||
// other, and then checking if the upper one has another correct byte.
|
||||
//This is potentially O(n), but for each matched byte, another iteration is removed from the outer
|
||||
// loop, so the sum of all calls is O(n).
|
||||
//
|
||||
//When the program approaches the end of the sorted area, it re-sorts twice as much as last time.
|
||||
// This gives O(log n) calls to the suffix sorter.
|
||||
//Given O(n log n) for one sorting step, the time taken is O(n/1 log n/1 + n/2 log n/2 +
|
||||
// n/4 log n/4 + ...), which is strictly less than O(n/1 log n + n/2 log n + n/4 log n + ...), which
|
||||
// equals O(2n log n), which is O(n log n). (The exact value of that infinite sum is 2n*log(n/2).)
|
||||
//
|
||||
//Many details were omitted from the above, but that's the basic setup.
|
||||
//
|
||||
//Thus, the program is O(max(n log n, n, n) = n log n) average and O(max(n log n, n^2, n) = n^2)
|
||||
// worst case.
|
||||
//
|
||||
//I conclude that the task of finding, understanding and implementing a sub-O(n^2) algorithm for
|
||||
// delta patching is resolved.
|
||||
|
||||
|
||||
//Known cases where this function does not emit the optimal encoding:
|
||||
//If a match in the target file would extend further than target_search_size, it is often skipped.
|
||||
// Penalty: O(log n), with extremely low constants (it'd require a >256B match to be exactly there).
|
||||
// Even for big files, the penalty is very likely to remain zero; even hitting double-digit bytes
|
||||
// would require a file designed exactly for that.
|
||||
//If multiple matches are equally good, it picks one at random, not the one that's cheaper to encode.
|
||||
// Penalty: Likely O(n) or O(n log log n), with low constants. I'd guess ~1.4% for my 48MB test file.
|
||||
//However, due to better heuristics and others' performance optimizations, this one still beats its
|
||||
// competitors.
|
||||
|
||||
|
||||
//Possible optimizations:
|
||||
//divsufsort() takes approximately 2/3 of the total time. create_reverse_index() takes roughly a third of the remainder.
|
||||
//Each iteration takes four times as long as the previous one.
|
||||
//If each iteration takes 4 times as long as the previous one, then the last one takes 3/4 of the total time.
|
||||
//Since divsufsort+create_reverse_index doesn't depend on anything else, the last iteration can be split off to its own thread.
|
||||
//This would split it to
|
||||
//Search, non-final: 2/9 * 1/4 = 2/36
|
||||
//Search, final: 2/9 * 3/4 = 6/36
|
||||
//Sort+rev, non-final: 7/9 * 1/4 = 7/36
|
||||
//Sort+rev, final: 7/9 * 3/4 = 21/36
|
||||
//All non-final must be done sequentially. Both Sort Final and non-final must be done before Search Final can start.
|
||||
//This means the final time, if Sort Final is split off, is
|
||||
//max(7/36+2/36, 21/36) + 6/36 = 27/36 = 3/4
|
||||
//of the original time.
|
||||
//Due to
|
||||
//- the considerable complexity costs (OpenMP doesn't seem able to represent the "insert a wait in
|
||||
// the middle of this while loop" I would need)
|
||||
//- the added memory use, approximately 25% higher - it's already high enough
|
||||
//- libdivsufsort already using threads, which would make the gains lower
|
||||
// and would increase complexity, as I have to ensure the big one remains threaded -
|
||||
// and that the small ones are not, as that'd starve the big one
|
||||
//I deem a possible 25% boost not worthwhile.
|
||||
|
||||
|
||||
//Both sorting algorithms claim O(1) memory use (in addition to the bytes and the output). In
|
||||
// addition to that, this algorithm uses (source.len*target.len)*(sizeof(uint8_t)+2*sizeof(off_t))
|
||||
// bytes of memory, plus the input and output files, plus the patch.
|
||||
//For most hardware, this is 9*(source.len+target.len), or 5*(source+target) for the slim one.
|
||||
|
||||
|
||||
#include "sais.cpp"
|
||||
template<typename sais_index_type>
|
||||
static void
|
||||
sufsort(sais_index_type* SA, const uint8_t* T, sais_index_type n) {
|
||||
if(n <= 1) { if(n == 1) SA[0] = 0; return; }
|
||||
sais_main<sais_index_type>(T, SA, 0, n, 256);
|
||||
}
|
||||
|
||||
//According to <https://code.google.com/p/libdivsufsort/wiki/SACA_Benchmarks>, divsufsort achieves
|
||||
// approximately half the time of SAIS for nearly all files, despite SAIS' promises of linear
|
||||
// performance (divsufsort claims O(n log n)).
|
||||
|
||||
//divsufsort only allocates O(1) for some radix/bucket sorting. SAIS seems constant too.
|
||||
//I'd prefer to let them allocate from an array I give it, but divsuf doesn't allow that, and there
|
||||
// are only half a dozen allocations per call anyways.
|
||||
|
||||
#ifdef USE_DIVSUFSORT
|
||||
#include "divsufsort.h"
|
||||
|
||||
static void sufsort(int32_t* SA, uint8_t* T, int32_t n)
|
||||
{
|
||||
divsufsort(T, SA, n);
|
||||
}
|
||||
#endif
|
||||
|
||||
#ifdef USE_DIVSUFSORT64
|
||||
#include "divsufsort64.h"
|
||||
|
||||
static void sufsort(int64_t* SA, uint8_t* T, int64_t n)
|
||||
{
|
||||
divsufsort(T, SA, n);
|
||||
}
|
||||
#endif
|
||||
|
||||
|
||||
|
||||
template<typename T> static T min(T a, T b) { return a<b ? a : b; }
|
||||
template<typename T> static T max(T a, T b) { return a<b ? b : a; }
|
||||
|
||||
|
||||
|
||||
namespace {
|
||||
struct bps_creator {
|
||||
uint8_t* out;
|
||||
size_t outlen;
|
||||
size_t outbuflen;
|
||||
|
||||
void reserve(size_t len)
|
||||
{
|
||||
if (outlen+len > outbuflen)
|
||||
{
|
||||
if (!outbuflen) outbuflen = 128;
|
||||
while (outlen+len > outbuflen) outbuflen *= 2;
|
||||
out = (uint8_t*)realloc(out, outbuflen);
|
||||
}
|
||||
}
|
||||
|
||||
void append(const uint8_t * data, size_t len)
|
||||
{
|
||||
reserve(len);
|
||||
memcpy(out+outlen, data, len);
|
||||
outlen+=len;
|
||||
}
|
||||
|
||||
void appendnum(size_t num)
|
||||
{
|
||||
#ifdef TEST_CORRECT
|
||||
if (num > 1000000000)
|
||||
printf("ERROR: Attempt to write %.8lX\n",(unsigned long)num),abort();
|
||||
#endif
|
||||
reserve(sizeof(size_t)*8/7+1);
|
||||
|
||||
while (num >= 128)
|
||||
{
|
||||
out[outlen++]=(num&0x7F);
|
||||
num>>=7;
|
||||
num--;
|
||||
}
|
||||
out[outlen++]=num|0x80;
|
||||
}
|
||||
|
||||
void appendnum32(uint32_t num)
|
||||
{
|
||||
reserve(4);
|
||||
out[outlen++] = num>>0;
|
||||
out[outlen++] = num>>8;
|
||||
out[outlen++] = num>>16;
|
||||
out[outlen++] = num>>24;
|
||||
}
|
||||
|
||||
size_t sourcelen;
|
||||
size_t targetlen;
|
||||
const uint8_t* targetmem;
|
||||
|
||||
enum bpscmd { SourceRead, TargetRead, SourceCopy, TargetCopy };
|
||||
|
||||
size_t outpos;
|
||||
|
||||
size_t sourcecopypos;
|
||||
size_t targetcopypos;
|
||||
|
||||
size_t numtargetread;
|
||||
|
||||
bps_creator(file* source, file* target, struct mem metadata)
|
||||
{
|
||||
outlen = 0;
|
||||
outbuflen = 128;
|
||||
out = (uint8_t*)malloc(outbuflen);
|
||||
|
||||
outpos = 0;
|
||||
|
||||
sourcelen = source->len();
|
||||
targetlen = target->len();
|
||||
|
||||
sourcecopypos = 0;
|
||||
targetcopypos = 0;
|
||||
|
||||
numtargetread = 0;
|
||||
|
||||
append((const uint8_t*)"BPS1", 4);
|
||||
appendnum(sourcelen);
|
||||
appendnum(targetlen);
|
||||
appendnum(metadata.len);
|
||||
append(metadata.ptr, metadata.len);
|
||||
|
||||
setProgress(NULL, NULL);
|
||||
}
|
||||
|
||||
|
||||
void move_target(const uint8_t* ptr)
|
||||
{
|
||||
targetmem = ptr;
|
||||
}
|
||||
|
||||
size_t encode_delta(size_t prev, size_t next)
|
||||
{
|
||||
bool negative = (next<prev);
|
||||
size_t offset = negative ? prev-next : next-prev;
|
||||
return (negative?1:0) | (offset<<1);
|
||||
}
|
||||
|
||||
void append_delta(size_t prev, size_t next)
|
||||
{
|
||||
appendnum(encode_delta(prev, next));
|
||||
}
|
||||
|
||||
void append_cmd(bpscmd command, size_t count)
|
||||
{
|
||||
appendnum((count-1)<<2 | command);
|
||||
}
|
||||
|
||||
void flush_target_read()
|
||||
{
|
||||
if (!numtargetread) return;
|
||||
append_cmd(TargetRead, numtargetread);
|
||||
append(targetmem+outpos-numtargetread, numtargetread);
|
||||
numtargetread = 0;
|
||||
}
|
||||
|
||||
size_t emit_source_copy(size_t location, size_t count)
|
||||
{
|
||||
if (location == outpos) return emit_source_read(location, count);
|
||||
flush_target_read();
|
||||
append_cmd(SourceCopy, count);
|
||||
append_delta(sourcecopypos, location);
|
||||
sourcecopypos = location+count;
|
||||
outpos += count;
|
||||
return count;
|
||||
}
|
||||
|
||||
size_t emit_source_read(size_t location, size_t count)
|
||||
{
|
||||
flush_target_read();
|
||||
#ifdef TEST_CORRECT
|
||||
if (location != outpos)
|
||||
puts("ERROR: SourceRead not from source pointer"),abort();
|
||||
#endif
|
||||
append_cmd(SourceRead, count);
|
||||
outpos+=count;
|
||||
return count;
|
||||
}
|
||||
|
||||
size_t emit_target_copy(size_t location, size_t count)
|
||||
{
|
||||
flush_target_read();
|
||||
append_cmd(TargetCopy, count);
|
||||
append_delta(targetcopypos, location);
|
||||
targetcopypos = location+count;
|
||||
outpos += count;
|
||||
return count;
|
||||
}
|
||||
|
||||
size_t emit_target_read()
|
||||
{
|
||||
numtargetread++;
|
||||
outpos++;
|
||||
return 1;
|
||||
}
|
||||
|
||||
|
||||
size_t abs_diff(size_t a, size_t b)
|
||||
{
|
||||
return (b<a) ? (a-b) : (b-a);
|
||||
}
|
||||
size_t num_cost(size_t num)
|
||||
{
|
||||
if (num<128) return 1;
|
||||
if (num<128*128) return 2; // 32KB
|
||||
if (num<128*128*128) return 3; // 2MB
|
||||
if (num<128*128*128*128) return 4; // 256MB
|
||||
return 5; // 128^5 is 32GB, let's just assume the sizes don't go any higher...
|
||||
}
|
||||
|
||||
bool use_match(bool hastargetread, size_t cost, size_t len)
|
||||
{
|
||||
//numbers calculated via trial and error; checking for each cost, optimizing 'len' for each, and checking what happens
|
||||
//then a pattern was identified and used
|
||||
//yes, it looks weird
|
||||
return len >= 1+cost+hastargetread+(len==1);
|
||||
}
|
||||
|
||||
|
||||
//Return value is how many bytes were used. If you believe the given one sucks, use TargetRead and return 1.
|
||||
size_t match(bool is_target, size_t pos, size_t len)
|
||||
{
|
||||
if (!use_match(
|
||||
numtargetread,
|
||||
(!is_target && pos==outpos) ? 1 : // SourceRead
|
||||
(num_cost(abs_diff(pos, (is_target ? targetcopypos : sourcecopypos)))+1),
|
||||
len
|
||||
))
|
||||
{
|
||||
return emit_target_read();
|
||||
}
|
||||
|
||||
if (is_target) return emit_target_copy(pos, len);
|
||||
else return emit_source_copy(pos, len);
|
||||
}
|
||||
|
||||
|
||||
bool (*prog_func)(void* userdata, size_t done, size_t total);
|
||||
void* prog_dat;
|
||||
|
||||
static bool prog_func_null(void* userdata, size_t done, size_t total) { return true; }
|
||||
|
||||
void setProgress(bool (*progress)(void* userdata, size_t done, size_t total), void* userdata)
|
||||
{
|
||||
if (!progress) progress = prog_func_null;
|
||||
|
||||
prog_func=progress;
|
||||
prog_dat=userdata;
|
||||
}
|
||||
|
||||
bool progress(size_t done, size_t total)
|
||||
{
|
||||
return prog_func(prog_dat, done, total);
|
||||
}
|
||||
|
||||
|
||||
void finish(const uint8_t* source, const uint8_t* target)
|
||||
{
|
||||
flush_target_read();
|
||||
#ifdef TEST_CORRECT
|
||||
if (outpos != targetlen)
|
||||
puts("ERROR: patch creates wrong ROM size"),abort();
|
||||
#endif
|
||||
|
||||
appendnum32(crc32(source, sourcelen));
|
||||
appendnum32(crc32(target, targetlen));
|
||||
appendnum32(crc32(out, outlen));
|
||||
}
|
||||
|
||||
struct mem getpatch()
|
||||
{
|
||||
struct mem ret = { out, outlen };
|
||||
out = NULL;
|
||||
return ret;
|
||||
}
|
||||
|
||||
~bps_creator() { free(out); }
|
||||
};
|
||||
}
|
||||
|
||||
|
||||
|
||||
#ifdef TEST_PERF
|
||||
static int match_len_n=0;
|
||||
static int match_len_tot=0;
|
||||
#endif
|
||||
|
||||
template<typename off_t>
|
||||
static off_t match_len(const uint8_t* a, const uint8_t* b, off_t len)
|
||||
{
|
||||
off_t i;
|
||||
for (i=0;i<len && a[i]==b[i];i++) {}
|
||||
#ifdef TEST_PERF
|
||||
match_len_n++;
|
||||
match_len_tot+=i;
|
||||
#endif
|
||||
return i;
|
||||
}
|
||||
|
||||
//This one assumes that the longest common prefix of 'a' and 'b' is shared also by 'search'.
|
||||
//In practice, lexographically, a < search < b, which is a stronger guarantee.
|
||||
template<typename off_t>
|
||||
static off_t pick_best_of_two(const uint8_t* search, off_t searchlen,
|
||||
const uint8_t* data, off_t datalen,
|
||||
off_t a, off_t b,
|
||||
off_t* bestlen)
|
||||
{
|
||||
off_t commonlen = match_len(data+a, data+b, min(datalen-a, datalen-b));
|
||||
if (commonlen>=searchlen)
|
||||
{
|
||||
*bestlen=searchlen;
|
||||
return a;
|
||||
}
|
||||
|
||||
if (a+commonlen<datalen && search[commonlen]==data[a+commonlen])
|
||||
{
|
||||
// a is better
|
||||
*bestlen = commonlen + match_len(search+commonlen, data+a+commonlen, min(searchlen, datalen-a)-commonlen);
|
||||
return a;
|
||||
}
|
||||
else
|
||||
{
|
||||
// b is better, or they're equal
|
||||
*bestlen = commonlen + match_len(search+commonlen, data+b+commonlen, min(searchlen, datalen-b)-commonlen);
|
||||
return b;
|
||||
}
|
||||
}
|
||||
|
||||
//This one takes a match, which is assumed optimal, and looks for the lexographically closest one
|
||||
// that either starts before 'maxstart', or starts at or after 'minstart'.
|
||||
template<typename off_t>
|
||||
static off_t adjust_match(off_t match, const uint8_t* search, off_t searchlen,
|
||||
const uint8_t* data,off_t datalen, off_t maxstart,off_t minstart,
|
||||
const off_t* sorted, off_t sortedlen,
|
||||
off_t* bestlen)
|
||||
{
|
||||
off_t match_up = match;
|
||||
off_t match_dn = match;
|
||||
while (match_up>=0 && sorted[match_up]>=maxstart && sorted[match_up]<minstart) match_up--;
|
||||
while (match_dn<sortedlen && sorted[match_dn]>=maxstart && sorted[match_dn]<minstart) match_dn++;
|
||||
if (match_up<0 || match_dn>=sortedlen)
|
||||
{
|
||||
if (match_up<0 && match_dn>=sortedlen)
|
||||
{
|
||||
*bestlen=0;
|
||||
return 0;
|
||||
}
|
||||
off_t pos = sorted[match_up<0 ? match_dn : match_up];
|
||||
*bestlen = match_len(search, data+pos, min(searchlen, datalen-pos));
|
||||
return pos;
|
||||
}
|
||||
|
||||
return pick_best_of_two(search,searchlen, data,datalen, sorted[match_up],sorted[match_dn], bestlen);
|
||||
}
|
||||
|
||||
|
||||
|
||||
static uint16_t read2_uc(const uint8_t* data)
|
||||
{
|
||||
return data[0]<<8 | data[1];
|
||||
}
|
||||
|
||||
template<typename off_t>
|
||||
static uint16_t read2(const uint8_t* data, off_t len)
|
||||
{
|
||||
if (len>=2) return read2_uc(data);
|
||||
else
|
||||
{
|
||||
uint16_t out = (EOF_IS_LAST ? 0xFFFF : 0x0000);
|
||||
if (len==1) out = (data[0]<<8) | (out&0x00FF);
|
||||
return out;
|
||||
}
|
||||
}
|
||||
|
||||
template<typename off_t>
|
||||
static void create_buckets(const uint8_t* data, off_t* index, off_t len, off_t* buckets)
|
||||
{
|
||||
off_t low = 0;
|
||||
off_t high;
|
||||
|
||||
for (int n=0;n<65536;n++)
|
||||
{
|
||||
//'low' remains from the previous iteration and is a known minimum
|
||||
high = low+(len/131072)+1; // optimal value: slightly above a third of the distance to the next one
|
||||
while (true)
|
||||
{
|
||||
if (high > len-1) break;
|
||||
|
||||
off_t pos = index[high];
|
||||
uint16_t here = read2(data+pos, len-pos);
|
||||
|
||||
if (here >= n) break;
|
||||
else
|
||||
{
|
||||
off_t diff = high-low;
|
||||
low = high;
|
||||
high = high+diff*2;
|
||||
}
|
||||
}
|
||||
if (high > len-1) high = len-1;
|
||||
|
||||
|
||||
while (low < high)
|
||||
{
|
||||
off_t mid = low + (high-low)/2;
|
||||
off_t midpos = index[mid];
|
||||
|
||||
uint16_t here = read2(data+midpos, len-midpos);
|
||||
if (here < n) low = mid+1;
|
||||
else high = mid;
|
||||
}
|
||||
buckets[n] = low;
|
||||
}
|
||||
|
||||
buckets[65536] = len;
|
||||
|
||||
#ifdef TEST_CORRECT
|
||||
if (buckets[0]!=0)
|
||||
{
|
||||
printf("e: buckets suck, [0]=%i\n", buckets[0]);
|
||||
abort();
|
||||
}
|
||||
for (int n=0;n<65536;n++)
|
||||
{
|
||||
off_t low = buckets[n];
|
||||
off_t high = buckets[n+1];
|
||||
for (off_t i=low;i<high;i++)
|
||||
{
|
||||
if (read2(data+index[i], len-index[i])!=n)
|
||||
{
|
||||
printf("e: buckets suck, %i != (%i)[%i]%i [%i-%i]", n, i,index[i],read2(data+index[i],len-index[i]),low,high);
|
||||
abort();
|
||||
}
|
||||
}
|
||||
//printf("%i:[%i]%i\n",n,low,read2(data+index[low],len-low));
|
||||
}
|
||||
#endif
|
||||
}
|
||||
|
||||
template<typename off_t>
|
||||
static off_t find_index(off_t pos, const uint8_t* data, off_t datalen, const off_t* index, const off_t* reverse, off_t* buckets)
|
||||
{
|
||||
if (reverse) return reverse[pos];
|
||||
|
||||
//if (datalen<2) return 0;
|
||||
uint16_t bucket = read2(data+pos, datalen-pos);
|
||||
//printf("p=%i b=%i\n",pos,bucket);
|
||||
|
||||
//TODO
|
||||
//off_t low = 0;
|
||||
//off_t high = datalen-1;
|
||||
off_t low = buckets[bucket];
|
||||
off_t high = buckets[bucket+1]-1;
|
||||
|
||||
off_t lowmatch = 2;
|
||||
off_t highmatch = 2;
|
||||
|
||||
//printf("b=%i r=%i(%i)-%i(%i)\n",bucket,low,read2(data+index[low],datalen-index[low]),high,read2(data+index[high],datalen-index[high]));
|
||||
//fflush(stdout);
|
||||
while (true)
|
||||
{
|
||||
off_t mid = low + (high-low)/2;
|
||||
off_t midpos = index[mid];
|
||||
if (midpos == pos) return mid;
|
||||
//printf("r=[%i]%i-%i \n",high-low,low,high,);
|
||||
//fflush(stdout);
|
||||
#ifdef TEST_CORRECT
|
||||
if (low >= high)
|
||||
{
|
||||
printf("E: [%i](%i): stuck at %i(%i)-%i(%i)\n", pos, read2_uc(data+pos),
|
||||
low, read2_uc(data+index[low]), high, read2_uc(data+index[high]));
|
||||
int n=0;
|
||||
while (index[n]!=pos) n++;
|
||||
printf("correct one is %i(%i)\n",n, read2_uc(data+index[n]));
|
||||
abort();
|
||||
}
|
||||
#endif
|
||||
|
||||
off_t matchlenstart = min(lowmatch, highmatch);
|
||||
|
||||
off_t len = datalen - max(pos, midpos) - matchlenstart;
|
||||
|
||||
const uint8_t* search = data+pos+matchlenstart;
|
||||
const uint8_t* here = data+midpos+matchlenstart;
|
||||
|
||||
while (len>0 && *search==*here)
|
||||
{
|
||||
search++;
|
||||
here++;
|
||||
len--;
|
||||
}
|
||||
|
||||
off_t matchlen = search-data-pos;
|
||||
|
||||
bool less;
|
||||
if (len > 0) less = (*here<*search);
|
||||
else less = (here > search) ^ EOF_IS_LAST;
|
||||
|
||||
if (less)
|
||||
{
|
||||
low = mid+1;
|
||||
lowmatch = matchlen;
|
||||
}
|
||||
else
|
||||
{
|
||||
high = mid-1;
|
||||
highmatch = matchlen;
|
||||
}
|
||||
|
||||
if (low+256 > high)
|
||||
{
|
||||
off_t i=low;
|
||||
while (true)
|
||||
{
|
||||
if (index[i]==pos) return i;
|
||||
i++;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
template<typename off_t>
|
||||
static void create_reverse_index(off_t* index, off_t* reverse, off_t len)
|
||||
{
|
||||
//testcase: linux 3.18.14 -> 4.0.4 .xz
|
||||
//without: real23.544 user32.930
|
||||
//with: real22.636 user40.168
|
||||
//'user' jumps up quite a lot, while 'real' only moves a short bit
|
||||
//I'm not sure why the tradeoff is so bad (do the cachelines bounce THAT badly?), but I deem it not worth it.
|
||||
//#pragma omp parallel for
|
||||
for (off_t i=0;i<len;i++) reverse[index[i]]=i;
|
||||
}
|
||||
|
||||
template<typename off_t>
|
||||
static off_t nextsize(off_t outpos, off_t sortedsize, off_t targetlen)
|
||||
{
|
||||
while (outpos >= sortedsize-256 && sortedsize < targetlen)
|
||||
sortedsize = min(sortedsize*4+3, targetlen);
|
||||
return sortedsize;
|
||||
}
|
||||
|
||||
template<typename off_t>
|
||||
off_t lerp(off_t x, off_t y, float frac)
|
||||
{
|
||||
return x + (y-x)*frac;
|
||||
}
|
||||
|
||||
template<typename off_t>
|
||||
static bpserror bps_create_suf_core(file* source, file* target, bool moremem, struct bps_creator * out)
|
||||
{
|
||||
bpserror err;
|
||||
|
||||
size_t realsourcelen = source->len();
|
||||
size_t realtargetlen = target->len();
|
||||
|
||||
size_t overflowtest = realsourcelen + realtargetlen;
|
||||
|
||||
//source+target length is bigger than size_t (how did that manage to get allocated?)
|
||||
if (overflowtest < realsourcelen) return bps_too_big;
|
||||
|
||||
//source+target doesn't fit in unsigned off_t
|
||||
if ((size_t)(off_t)overflowtest != overflowtest) return bps_too_big;
|
||||
|
||||
//source+target doesn't fit in signed off_t
|
||||
if ((off_t)overflowtest < 0) return bps_too_big;
|
||||
|
||||
//the mallocs would overflow
|
||||
if ((size_t)realsourcelen+realtargetlen >= SIZE_MAX/sizeof(off_t)) return bps_too_big;
|
||||
|
||||
|
||||
off_t sourcelen = realsourcelen;
|
||||
off_t targetlen = realtargetlen;
|
||||
|
||||
uint8_t* mem_joined = (uint8_t*)malloc(sizeof(uint8_t)*(sourcelen+targetlen));
|
||||
|
||||
off_t* sorted = (off_t*)malloc(sizeof(off_t)*(sourcelen+targetlen));
|
||||
|
||||
off_t* sorted_inverse = NULL;
|
||||
if (moremem) sorted_inverse = (off_t*)malloc(sizeof(off_t)*(sourcelen+targetlen));
|
||||
|
||||
off_t* buckets = NULL;
|
||||
if (!sorted_inverse) buckets = (off_t*)malloc(sizeof(off_t)*65537);
|
||||
|
||||
if (!sorted || !mem_joined || (!sorted_inverse && !buckets))
|
||||
{
|
||||
free(mem_joined);
|
||||
free(sorted);
|
||||
free(sorted_inverse);
|
||||
free(buckets);
|
||||
return bps_out_of_mem;
|
||||
}
|
||||
|
||||
//sortedsize is how much of the target file is sorted
|
||||
off_t sortedsize = targetlen;
|
||||
//divide by 4 for each iteration, to avoid sorting 50% of the file (the sorter is slow)
|
||||
while (sortedsize/4 > sourcelen && sortedsize > 1024) sortedsize >>= 2;
|
||||
|
||||
off_t prevsortedsize = 0;
|
||||
off_t outpos = 0;
|
||||
|
||||
goto reindex; // jump into the middle so I won't need a special case to enter it
|
||||
|
||||
while (outpos < targetlen)
|
||||
{
|
||||
if (outpos >= sortedsize-256 && sortedsize < targetlen)
|
||||
{
|
||||
sortedsize = nextsize(outpos, sortedsize, targetlen);
|
||||
|
||||
reindex:
|
||||
|
||||
//this isn't an exact science
|
||||
const float percSort = sorted_inverse ? 0.67 : 0.50;
|
||||
const float percInv = sorted_inverse ? 0.11 : 0.10;
|
||||
//const float percFind = sorted_inverse ? 0.22 : 0.40; // unused
|
||||
|
||||
const size_t progPreSort = lerp(prevsortedsize, sortedsize, 0);
|
||||
const size_t progPreInv = lerp(prevsortedsize, sortedsize, percSort);
|
||||
const size_t progPreFind = lerp(prevsortedsize, sortedsize, percSort+percInv);
|
||||
|
||||
prevsortedsize = sortedsize;
|
||||
|
||||
if (!out->progress(progPreSort, targetlen))
|
||||
{
|
||||
err = bps_canceled;
|
||||
goto error;
|
||||
}
|
||||
|
||||
target->read(mem_joined, 0, sortedsize);
|
||||
source->read(mem_joined+sortedsize, 0, sourcelen);
|
||||
out->move_target(mem_joined);
|
||||
sufsort(sorted, mem_joined, sortedsize+sourcelen);
|
||||
|
||||
if (!out->progress(progPreInv, targetlen))
|
||||
{
|
||||
err = bps_canceled;
|
||||
goto error;
|
||||
}
|
||||
|
||||
if (sorted_inverse)
|
||||
create_reverse_index(sorted, sorted_inverse, sortedsize+sourcelen);
|
||||
else
|
||||
create_buckets(mem_joined, sorted, sortedsize+sourcelen, buckets);
|
||||
|
||||
if (!out->progress(progPreFind, targetlen))
|
||||
{
|
||||
err = bps_canceled;
|
||||
goto error;
|
||||
}
|
||||
}
|
||||
|
||||
off_t matchlen = 0;
|
||||
off_t matchpos = adjust_match(find_index(outpos, mem_joined, sortedsize+sourcelen, sorted, sorted_inverse, buckets),
|
||||
mem_joined+outpos, sortedsize-outpos,
|
||||
mem_joined,sortedsize+sourcelen, outpos,sortedsize,
|
||||
sorted, sortedsize+sourcelen,
|
||||
&matchlen);
|
||||
|
||||
#ifdef TEST_CORRECT
|
||||
if (matchlen && matchpos >= outpos && matchpos < sortedsize) puts("ERROR: found match in invalid location"),abort();
|
||||
if (memcmp(mem_joined+matchpos, mem_joined+outpos, matchlen)) puts("ERROR: found match doesn't match"),abort();
|
||||
#endif
|
||||
|
||||
off_t taken;
|
||||
if (matchpos >= sortedsize) taken = out->match(false, matchpos-sortedsize, matchlen);
|
||||
else taken = out->match(true, matchpos, matchlen);
|
||||
#ifdef TEST_CORRECT
|
||||
if (taken < 0) puts("ERROR: match() returned negative"),abort();
|
||||
if (matchlen >= 7 && taken < matchlen) printf("ERROR: match() took %i bytes, offered %i\n", taken, matchlen),abort();
|
||||
#endif
|
||||
outpos += taken;
|
||||
}
|
||||
|
||||
out->finish(mem_joined+sortedsize, mem_joined);
|
||||
|
||||
err = bps_ok;
|
||||
|
||||
error:
|
||||
free(buckets);
|
||||
free(sorted_inverse);
|
||||
free(sorted);
|
||||
free(mem_joined);
|
||||
|
||||
return err;
|
||||
}
|
||||
|
||||
|
||||
template<typename T> static bpserror bps_create_suf_pick(file* source, file* target, bool moremem, struct bps_creator * bps);
|
||||
template<> bpserror bps_create_suf_pick<uint32_t>(file* source, file* target, bool moremem, struct bps_creator * bps)
|
||||
{
|
||||
return bps_create_suf_core<int32_t>(source, target, moremem, bps);
|
||||
}
|
||||
template<> bpserror bps_create_suf_pick<uint64_t>(file* source, file* target, bool moremem, struct bps_creator * bps)
|
||||
{
|
||||
bpserror err = bps_create_suf_core<int32_t>(source, target, moremem, bps);
|
||||
if (err==bps_too_big) err = bps_create_suf_core<int64_t>(source, target, moremem, bps);
|
||||
return err;
|
||||
}
|
||||
|
||||
//This one picks a function based on 32-bit integers if that fits. This halves memory use for common inputs.
|
||||
//It also handles some stuff related to the BPS headers and footers.
|
||||
extern "C"
|
||||
bpserror bps_create_delta(file* source, file* target, struct mem metadata, struct mem * patchmem,
|
||||
bool (*progress)(void* userdata, size_t done, size_t total), void* userdata, bool moremem)
|
||||
{
|
||||
bps_creator bps(source, target, metadata);
|
||||
bps.setProgress(progress, userdata);
|
||||
|
||||
size_t maindata = bps.outlen;
|
||||
|
||||
//off_t must be signed
|
||||
bpserror err = bps_create_suf_pick<size_t>(source, target, moremem, &bps);
|
||||
if (err!=bps_ok) return err;
|
||||
|
||||
*patchmem = bps.getpatch();
|
||||
|
||||
while ((patchmem->ptr[maindata]&0x80) == 0x00) maindata++;
|
||||
if (maindata==patchmem->len-12-1) return bps_identical;
|
||||
return bps_ok;
|
||||
}
|
||||
|
||||
|
||||
|
||||
|
||||
#ifdef BPS_STANDALONE
|
||||
#include <stdio.h>
|
||||
static struct mem ReadWholeFile(const char * filename)
|
||||
{
|
||||
struct mem null = {NULL, 0};
|
||||
|
||||
FILE * file=fopen(filename, "rb");
|
||||
if (!file) return null;
|
||||
fseek(file, 0, SEEK_END);
|
||||
size_t len=ftell(file);
|
||||
fseek(file, 0, SEEK_SET);
|
||||
unsigned char * data=(unsigned char*)malloc(len);
|
||||
size_t truelen=fread(data, 1,len, file);
|
||||
fclose(file);
|
||||
if (len!=truelen)
|
||||
{
|
||||
free(data);
|
||||
return null;
|
||||
}
|
||||
|
||||
struct mem ret = { (unsigned char*)data, len };
|
||||
return ret;
|
||||
}
|
||||
static bool WriteWholeFile(const char * filename, struct mem data)
|
||||
{
|
||||
FILE * file=fopen(filename, "wb");
|
||||
if (!file) return false;
|
||||
unsigned int truelen=fwrite(data.ptr, 1,data.len, file);
|
||||
fclose(file);
|
||||
return (truelen==data.len);
|
||||
}
|
||||
int main(int argc, char * argv[])
|
||||
{
|
||||
//struct mem out = ReadWholeFile(argv[2]);
|
||||
//printf("check=%.8X\n",crc32(out.ptr, out.len));
|
||||
|
||||
struct mem in = ReadWholeFile(argv[1]);
|
||||
struct mem out = ReadWholeFile(argv[2]);
|
||||
struct mem null = {NULL, 0};
|
||||
struct mem p={NULL,0};
|
||||
//int n=50;
|
||||
//for(int i=0;i<n;i++)
|
||||
//printf("%i/%i\n",i,n),
|
||||
bps_create_delta(in,out,null,&p, NULL,NULL);
|
||||
printf("len=%lu \n",p.len);
|
||||
printf("check=%.8X\n",*(uint32_t*)(p.ptr+p.len-4));
|
||||
WriteWholeFile(argv[3], p);
|
||||
free(in.ptr);
|
||||
free(out.ptr);
|
||||
free(p.ptr);
|
||||
|
||||
#ifdef TEST_PERF
|
||||
printf("%i/%i=%f\n",match_len_tot,match_len_n,(float)match_len_tot/match_len_n);
|
||||
#endif
|
||||
}
|
||||
#endif
|
||||
Reference in New Issue
Block a user