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qtermwidget-packaging/lib/BlockArray.cpp

380 lines
7.8 KiB

/*
This file is part of Konsole, an X terminal.
Copyright (C) 2000 by Stephan Kulow <coolo@kde.org>
Rewritten for QT4 by e_k <e_k at users.sourceforge.net>, Copyright (C)2008
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 <QtDebug>
// Own
#include "BlockArray.h"
// System
#include <assert.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <unistd.h>
#include <stdio.h>
using namespace Konsole;
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) {
qDebug() << "BlockArray::at() i > index\n";
return 0;
}
// if (index - i >= length) {
// kDebug(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)
{
// kDebug(1211) << "setHistorySize " << size << " " << newsize;
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);
}