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tdebase/konsole/konsole/BlockArray.cpp

328 lines
7.3 KiB

/*
This file is part of Konsole, an X terminal.
Copyright (C) 2000 by Stephan Kulow <coolo@kde.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program 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 for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.
*/
#include "BlockArray.h"
#include <assert.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <unistd.h>
#include <stdio.h>
#include <kdebug.h>
static int blocksize = 0;
BlockArray::BlockArray()
: size(0),
current(size_t(-1)),
index(size_t(-1)),
lastmap(0),
lastmap_index(size_t(-1)),
lastblock(0), ion(-1),
length(0)
{
// lastmap_index = index = current = size_t(-1);
if (blocksize == 0)
blocksize = ((sizeof(Block) / getpagesize()) + 1) * getpagesize();
}
BlockArray::~BlockArray()
{
setHistorySize(0);
assert(!lastblock);
}
size_t BlockArray::append(Block *block)
{
if (!size)
return size_t(-1);
++current;
if (current >= size) current = 0;
int rc;
rc = lseek(ion, current * blocksize, SEEK_SET); if (rc < 0) { perror("HistoryBuffer::add.seek"); setHistorySize(0); return size_t(-1); }
rc = write(ion, block, blocksize); if (rc < 0) { perror("HistoryBuffer::add.write"); setHistorySize(0); return size_t(-1); }
length++;
if (length > size) length = size;
++index;
delete block;
return current;
}
size_t BlockArray::newBlock()
{
if (!size)
return size_t(-1);
append(lastblock);
lastblock = new Block();
return index + 1;
}
Block *BlockArray::lastBlock() const
{
return lastblock;
}
bool BlockArray::has(size_t i) const
{
if (i == index + 1)
return true;
if (i > index)
return false;
if (index - i >= length)
return false;
return true;
}
const Block* BlockArray::at(size_t i)
{
if (i == index + 1)
return lastblock;
if (i == lastmap_index)
return lastmap;
if (i > index) {
kdDebug(1211) << "BlockArray::at() i > index\n";
return 0;
}
// if (index - i >= length) {
// kdDebug(1211) << "BlockArray::at() index - i >= length\n";
// return 0;
// }
size_t j = i; // (current - (index - i) + (index/size+1)*size) % size ;
assert(j < size);
unmap();
Block *block = (Block*)mmap(0, blocksize, PROT_READ, MAP_PRIVATE, ion, j * blocksize);
if (block == (Block*)-1) { perror("mmap"); return 0; }
lastmap = block;
lastmap_index = i;
return block;
}
void BlockArray::unmap()
{
if (lastmap) {
int res = munmap((char*)lastmap, blocksize);
if (res < 0) perror("munmap");
}
lastmap = 0;
lastmap_index = size_t(-1);
}
bool BlockArray::setSize(size_t newsize)
{
return setHistorySize(newsize * 1024 / blocksize);
}
bool BlockArray::setHistorySize(size_t newsize)
{
// kdDebug(1211) << "setHistorySize " << size << " " << newsize << endl;
if (size == newsize)
return false;
unmap();
if (!newsize) {
delete lastblock;
lastblock = 0;
if (ion >= 0) close(ion);
ion = -1;
current = size_t(-1);
return true;
}
if (!size) {
FILE* tmp = tmpfile();
if (!tmp) {
perror("konsole: cannot open temp file.\n");
} else {
ion = dup(fileno(tmp));
if (ion<0) {
perror("konsole: cannot dup temp file.\n");
fclose(tmp);
}
}
if (ion < 0)
return false;
assert(!lastblock);
lastblock = new Block();
size = newsize;
return false;
}
if (newsize > size) {
increaseBuffer();
size = newsize;
return false;
} else {
decreaseBuffer(newsize);
ftruncate(ion, length*blocksize);
size = newsize;
return true;
}
}
void moveBlock(FILE *fion, int cursor, int newpos, char *buffer2)
{
int res = fseek(fion, cursor * blocksize, SEEK_SET);
if (res)
perror("fseek");
res = fread(buffer2, blocksize, 1, fion);
if (res != 1)
perror("fread");
res = fseek(fion, newpos * blocksize, SEEK_SET);
if (res)
perror("fseek");
res = fwrite(buffer2, blocksize, 1, fion);
if (res != 1)
perror("fwrite");
// printf("moving block %d to %d\n", cursor, newpos);
}
void BlockArray::decreaseBuffer(size_t newsize)
{
if (index < newsize) // still fits in whole
return;
int offset = (current - (newsize - 1) + size) % size;
if (!offset)
return;
// The Block constructor could do somthing in future...
char *buffer1 = new char[blocksize];
FILE *fion = fdopen(dup(ion), "w+b");
if (!fion) {
delete [] buffer1;
perror("fdopen/dup");
return;
}
int firstblock;
if (current <= newsize) {
firstblock = current + 1;
} else {
firstblock = 0;
}
size_t oldpos;
for (size_t i = 0, cursor=firstblock; i < newsize; i++) {
oldpos = (size + cursor + offset) % size;
moveBlock(fion, oldpos, cursor, buffer1);
if (oldpos < newsize) {
cursor = oldpos;
} else
cursor++;
}
current = newsize - 1;
length = newsize;
delete [] buffer1;
fclose(fion);
}
void BlockArray::increaseBuffer()
{
if (index < size) // not even wrapped once
return;
int offset = (current + size + 1) % size;
if (!offset) // no moving needed
return;
// The Block constructor could do somthing in future...
char *buffer1 = new char[blocksize];
char *buffer2 = new char[blocksize];
int runs = 1;
int bpr = size; // blocks per run
if (size % offset == 0) {
bpr = size / offset;
runs = offset;
}
FILE *fion = fdopen(dup(ion), "w+b");
if (!fion) {
perror("fdopen/dup");
delete [] buffer1;
delete [] buffer2;
return;
}
int res;
for (int i = 0; i < runs; i++)
{
// free one block in chain
int firstblock = (offset + i) % size;
res = fseek(fion, firstblock * blocksize, SEEK_SET);
if (res)
perror("fseek");
res = fread(buffer1, blocksize, 1, fion);
if (res != 1)
perror("fread");
int newpos = 0;
for (int j = 1, cursor=firstblock; j < bpr; j++)
{
cursor = (cursor + offset) % size;
newpos = (cursor - offset + size) % size;
moveBlock(fion, cursor, newpos, buffer2);
}
res = fseek(fion, i * blocksize, SEEK_SET);
if (res)
perror("fseek");
res = fwrite(buffer1, blocksize, 1, fion);
if (res != 1)
perror("fwrite");
}
current = size - 1;
length = size;
delete [] buffer1;
delete [] buffer2;
fclose(fion);
}