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/**
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* Copyright (c) 2007-2012, Timothy Stack
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*
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* * Redistributions of source code must retain the above copyright notice, this
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* list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* * Neither the name of Timothy Stack nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* @file line_buffer.cc
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*/
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#include "config.h"
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#include <stdio.h>
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#include <errno.h>
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#include <string.h>
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#include <fcntl.h>
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#include <unistd.h>
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#ifdef HAVE_BZLIB_H
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#include <bzlib.h>
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#endif
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#include <set>
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#include "line_buffer.hh"
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using namespace std;
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static const size_t DEFAULT_LINE_BUFFER_SIZE = 256 * 1024;
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static const size_t MAX_LINE_BUFFER_SIZE = 4 * DEFAULT_LINE_BUFFER_SIZE;
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static const size_t DEFAULT_INCREMENT = 128 * 1024;
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static const size_t MAX_COMPRESSED_BUFFER_SIZE = 32 * 1024 * 1024;
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/*
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* XXX REMOVE ME
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*
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* The stock gzipped file code does not use pread, so we need to use a lock to
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* get exclusive access to the file. In the future, we should just rewrite
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* the gzipped file code to use pread.
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*/
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class lock_hack {
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public:
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class guard {
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public:
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guard() : g_lock(lock_hack::singleton())
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{
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this->g_lock.lock();
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};
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~guard()
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{
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this->g_lock.unlock();
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};
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private:
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lock_hack &g_lock;
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};
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static lock_hack &singleton()
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{
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static lock_hack retval;
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return retval;
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};
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void lock()
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{
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lockf(this->lh_fd, F_LOCK, 0);
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};
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void unlock()
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{
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lockf(this->lh_fd, F_ULOCK, 0);
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};
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private:
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lock_hack()
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{
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char lockname[64];
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snprintf(lockname, sizeof(lockname), "/tmp/lnav.%d.lck", getpid());
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this->lh_fd = open(lockname, O_CREAT | O_RDWR, 0600);
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fcntl(this->lh_fd, F_SETFD, FD_CLOEXEC);
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unlink(lockname);
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};
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int lh_fd;
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};
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/* XXX END */
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line_buffer::line_buffer()
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: lb_gz_file(NULL),
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lb_bz_file(false),
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lb_gz_offset(0),
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lb_file_size((size_t)-1),
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lb_file_offset(0),
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lb_file_time(0),
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lb_buffer_size(0),
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lb_buffer_max(DEFAULT_LINE_BUFFER_SIZE),
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lb_seekable(false),
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lb_last_line_offset(-1)
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{
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if ((this->lb_buffer = (char *)malloc(this->lb_buffer_max)) == NULL) {
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throw bad_alloc();
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}
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ensure(this->invariant());
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}
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line_buffer::~line_buffer()
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{
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auto_fd fd = -1;
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// Make sure any shared refs take ownership of the data.
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this->lb_share_manager.invalidate_refs();
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this->set_fd(fd);
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}
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void line_buffer::set_fd(auto_fd &fd)
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throw (error)
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{
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off_t newoff = 0;
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if (this->lb_gz_file) {
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gzclose(this->lb_gz_file);
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this->lb_gz_file = NULL;
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}
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if (this->lb_bz_file) {
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this->lb_bz_file = false;
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}
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if (fd != -1) {
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/* Sync the fd's offset with the object. */
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newoff = lseek(fd, 0, SEEK_CUR);
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if (newoff == -1) {
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if (errno != ESPIPE) {
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throw error(errno);
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}
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/* It's a pipe, start with a zero offset. */
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newoff = 0;
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this->lb_seekable = false;
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}
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else {
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char gz_id[2 + 1 + 1 + 4];
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if (pread(fd, gz_id, sizeof(gz_id), 0) == sizeof(gz_id)) {
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if (gz_id[0] == '\037' && gz_id[1] == '\213') {
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int gzfd = dup(fd);
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fcntl(gzfd, F_SETFD, FD_CLOEXEC);
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lseek(fd, 0, SEEK_SET);
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if ((this->lb_gz_file = gzdopen(gzfd, "r")) == NULL) {
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if (errno == 0) {
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throw bad_alloc();
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}
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else{
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throw error(errno);
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}
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}
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this->lb_file_time = *((int32_t *)&gz_id[4]);
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if (this->lb_file_time < 0)
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this->lb_file_time = 0;
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this->lb_gz_offset = lseek(this->lb_fd, 0, SEEK_CUR);
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}
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#ifdef HAVE_BZLIB_H
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else if (gz_id[0] == 'B' && gz_id[1] == 'Z') {
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lseek(fd, 0, SEEK_SET);
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this->lb_bz_file = true;
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/*
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* Loading data from a bzip2 file is pretty slow, so we try
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* to keep as much in memory as possible.
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*/
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this->resize_buffer(MAX_COMPRESSED_BUFFER_SIZE);
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}
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#endif
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}
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this->lb_seekable = true;
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}
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}
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this->lb_file_offset = newoff;
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this->lb_buffer_size = 0;
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this->lb_fd = fd;
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ensure(this->invariant());
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}
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void line_buffer::resize_buffer(size_t new_max)
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throw (error)
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{
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char *tmp, *old;
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require(this->lb_bz_file || this->lb_gz_file ||
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new_max <= MAX_LINE_BUFFER_SIZE);
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/* Still need more space, try a realloc. */
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old = this->lb_buffer.release();
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tmp = (char *)realloc(old, new_max);
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if (tmp != NULL) {
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this->lb_buffer = tmp;
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this->lb_buffer_max = new_max;
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}
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else {
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this->lb_buffer = old;
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throw error(ENOMEM);
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}
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}
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void line_buffer::ensure_available(off_t start, size_t max_length)
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throw (error)
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{
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size_t prefill, available;
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require(max_length <= MAX_LINE_BUFFER_SIZE);
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/*
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* Check to see if the start is inside the cached range or immediately
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* after.
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*/
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if (start < this->lb_file_offset ||
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start > (off_t)(this->lb_file_offset + this->lb_buffer_size)) {
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/*
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* The request is outside the cached range, need to reload the
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* whole thing.
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*/
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prefill = 0;
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this->lb_buffer_size = 0;
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if ((this->lb_file_size != (size_t)-1) &&
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(start + this->lb_buffer_max > this->lb_file_size)) {
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/*
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* If the start is near the end of the file, move the offset back a
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* bit so we can get more of the file in the cache.
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*/
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this->lb_file_offset = this->lb_file_size -
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std::min(this->lb_file_size,
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this->lb_buffer_max);
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}
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else {
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this->lb_file_offset = start;
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}
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}
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else {
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/* The request is in the cached range. Record how much extra data is in
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* the buffer before the requested range.
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*/
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prefill = start - this->lb_file_offset;
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}
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require(this->lb_file_offset <= start);
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require(prefill <= this->lb_buffer_size);
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available = this->lb_buffer_max - (start - this->lb_file_offset);
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require(available <= this->lb_buffer_max);
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if (max_length > available) {
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/*
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* Need more space, move any existing data to the front of the
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* buffer.
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*/
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this->lb_buffer_size -= prefill;
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this->lb_file_offset += prefill;
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memmove(&this->lb_buffer[0],
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&this->lb_buffer[prefill],
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this->lb_buffer_size);
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available = this->lb_buffer_max - (start - this->lb_file_offset);
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if (max_length > available) {
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this->resize_buffer(this->lb_buffer_max +
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DEFAULT_LINE_BUFFER_SIZE);
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}
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this->lb_share_manager.invalidate_refs();
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}
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}
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bool line_buffer::fill_range(off_t start, size_t max_length)
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throw (error)
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{
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bool retval = false;
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require(start >= 0);
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if (this->in_range(start) && this->in_range(start + max_length - 1)) {
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/* Cache already has the data, nothing to do. */
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retval = true;
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}
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else if (this->lb_fd != -1) {
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ssize_t rc;
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/* Make sure there is enough space, then */
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this->ensure_available(start, max_length);
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/* ... read in the new data. */
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if (this->lb_gz_file) {
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if (this->lb_file_size != (size_t)-1 &&
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this->in_range(start) &&
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this->in_range(this->lb_file_size - 1)) {
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rc = 0;
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}
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else {
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lock_hack::guard guard;
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lseek(this->lb_fd, this->lb_gz_offset, SEEK_SET);
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gzseek(this->lb_gz_file,
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this->lb_file_offset + this->lb_buffer_size,
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SEEK_SET);
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rc = gzread(this->lb_gz_file,
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&this->lb_buffer[this->lb_buffer_size],
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this->lb_buffer_max - this->lb_buffer_size);
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this->lb_gz_offset = lseek(this->lb_fd, 0, SEEK_CUR);
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}
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}
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#ifdef HAVE_BZLIB_H
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else if (this->lb_bz_file) {
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if (this->lb_file_size != (size_t)-1 &&
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(((size_t)start >= this->lb_file_size) ||
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(this->in_range(start) &&
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this->in_range(this->lb_file_size - 1)))) {
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rc = 0;
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}
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else {
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lock_hack::guard guard;
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char scratch[32 * 1024];
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BZFILE * bz_file;
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off_t seek_to;
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/*
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* Unfortunately, there is no bzseek, so we need to reopen the
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* file every time we want to do a read.
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*/
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lseek(this->lb_fd, 0, SEEK_SET);
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if ((bz_file = BZ2_bzdopen(dup(this->lb_fd), "r")) == NULL) {
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if (errno == 0) {
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throw bad_alloc();
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}
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else{
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throw error(errno);
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}
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}
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seek_to = this->lb_file_offset + this->lb_buffer_size;
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while (seek_to > 0) {
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int count;
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count = BZ2_bzread(bz_file,
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scratch,
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std::min((size_t)seek_to,
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sizeof(scratch)));
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seek_to -= count;
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}
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rc = BZ2_bzread(bz_file,
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&this->lb_buffer[this->lb_buffer_size],
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this->lb_buffer_max - this->lb_buffer_size);
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BZ2_bzclose(bz_file);
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if (rc != -1 && (
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rc < (this->lb_buffer_max - this->lb_buffer_size))) {
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this->lb_file_size = (
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this->lb_file_offset + this->lb_buffer_size + rc);
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}
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}
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}
|
|
|
|
#endif
|
|
|
|
else if (this->lb_seekable) {
|
|
|
|
rc = pread(this->lb_fd,
|
|
|
|
&this->lb_buffer[this->lb_buffer_size],
|
|
|
|
this->lb_buffer_max - this->lb_buffer_size,
|
|
|
|
this->lb_file_offset + this->lb_buffer_size);
|
|
|
|
}
|
|
|
|
else {
|
|
|
|
rc = read(this->lb_fd,
|
|
|
|
&this->lb_buffer[this->lb_buffer_size],
|
|
|
|
this->lb_buffer_max - this->lb_buffer_size);
|
|
|
|
}
|
|
|
|
// XXX For some reason, cygwin is giving us a bogus return value when
|
|
|
|
// up to the end of the file.
|
|
|
|
if (rc > (this->lb_buffer_max - this->lb_buffer_size)) {
|
|
|
|
rc = -1;
|
|
|
|
#ifdef ENODATA
|
|
|
|
errno = ENODATA;
|
|
|
|
#else
|
|
|
|
errno = EAGAIN;
|
|
|
|
#endif
|
|
|
|
}
|
|
|
|
switch (rc) {
|
|
|
|
case 0:
|
|
|
|
if (!this->lb_seekable) {
|
|
|
|
this->lb_file_size = this->lb_file_offset + this->lb_buffer_size;
|
|
|
|
}
|
|
|
|
if (start < (off_t) this->lb_file_size) {
|
|
|
|
retval = true;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (this->lb_gz_file || this->lb_bz_file) {
|
|
|
|
/*
|
|
|
|
* For compressed files, increase the buffer size so we don't
|
|
|
|
* have to spend as much time uncompressing the data.
|
|
|
|
*/
|
|
|
|
this->resize_buffer(MAX_COMPRESSED_BUFFER_SIZE);
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case (ssize_t)-1:
|
|
|
|
switch (errno) {
|
|
|
|
#ifdef ENODATA
|
|
|
|
/* Cygwin seems to return this when pread reaches the end of the */
|
|
|
|
/* file. */
|
|
|
|
case ENODATA:
|
|
|
|
#endif
|
|
|
|
case EINTR:
|
|
|
|
case EAGAIN:
|
|
|
|
break;
|
|
|
|
|
|
|
|
default:
|
|
|
|
throw error(errno);
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
default:
|
|
|
|
this->lb_buffer_size += rc;
|
|
|
|
retval = true;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
ensure(this->lb_buffer_size <= this->lb_buffer_max);
|
|
|
|
}
|
|
|
|
|
|
|
|
return retval;
|
|
|
|
}
|
|
|
|
|
|
|
|
bool line_buffer::read_line(off_t &offset, line_value &lv, bool include_delim)
|
|
|
|
throw (error)
|
|
|
|
{
|
|
|
|
size_t request_size = DEFAULT_INCREMENT;
|
|
|
|
bool retval = false;
|
|
|
|
|
|
|
|
require(this->lb_fd != -1);
|
|
|
|
|
|
|
|
if (this->lb_last_line_offset != -1 && offset >
|
|
|
|
this->lb_last_line_offset) {
|
|
|
|
/*
|
|
|
|
* Don't return anything past the last known line. The caller needs
|
|
|
|
* to try reading at the offset of the last line again.
|
|
|
|
*/
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
lv.lv_len = 0;
|
|
|
|
lv.lv_partial = false;
|
|
|
|
while (!retval) {
|
|
|
|
char *line_start, *lf;
|
|
|
|
|
|
|
|
this->fill_range(offset, request_size);
|
|
|
|
|
|
|
|
/* Find the data in the cache and */
|
|
|
|
line_start = this->get_range(offset, lv.lv_len);
|
|
|
|
/* ... look for the end-of-line or end-of-file. */
|
|
|
|
if (((lf = (char *)memchr(line_start, '\n', lv.lv_len)) != NULL) ||
|
|
|
|
(lv.lv_len >= MAX_LINE_BUFFER_SIZE) ||
|
|
|
|
(request_size == MAX_LINE_BUFFER_SIZE) ||
|
|
|
|
((request_size > lv.lv_len) && lv.lv_len > 0)) {
|
|
|
|
if ((lf != NULL) &&
|
|
|
|
((lf - line_start) >= MAX_LINE_BUFFER_SIZE - 1)) {
|
|
|
|
lf = NULL;
|
|
|
|
}
|
|
|
|
if (lf != NULL) {
|
|
|
|
lv.lv_partial = false;
|
|
|
|
lv.lv_len = lf - line_start;
|
|
|
|
if (include_delim) {
|
|
|
|
lv.lv_len += 1;
|
|
|
|
}
|
|
|
|
else {
|
|
|
|
offset += 1; /* Skip the delimiter. */
|
|
|
|
}
|
|
|
|
if (offset >= this->lb_last_line_offset) {
|
|
|
|
this->lb_last_line_offset = offset + lv.lv_len;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
else {
|
|
|
|
if (lv.lv_len >= MAX_LINE_BUFFER_SIZE) {
|
|
|
|
lv.lv_len = MAX_LINE_BUFFER_SIZE - 1;
|
|
|
|
lv.lv_partial = false;
|
|
|
|
}
|
|
|
|
else {
|
|
|
|
lv.lv_partial = true;
|
|
|
|
}
|
|
|
|
/*
|
|
|
|
* Be nice and make sure there is room for the caller to
|
|
|
|
* add a NULL-terminator.
|
|
|
|
*/
|
|
|
|
this->ensure_available(offset, lv.lv_len + 1);
|
|
|
|
line_start = this->get_range(offset, lv.lv_len);
|
|
|
|
|
|
|
|
if (lv.lv_len >= MAX_LINE_BUFFER_SIZE) {
|
|
|
|
lv.lv_len = MAX_LINE_BUFFER_SIZE - 1;
|
|
|
|
}
|
|
|
|
if (lv.lv_partial) {
|
|
|
|
/*
|
|
|
|
* Since no delimiter was seen, we need to remember the offset
|
|
|
|
* of the last line in the file so we don't mistakenly return
|
|
|
|
* two partial lines to the caller.
|
|
|
|
*
|
|
|
|
* 1. read_line() - returns partial line
|
|
|
|
* 2. file is written
|
|
|
|
* 3. read_line() - returns the middle of partial line.
|
|
|
|
*/
|
|
|
|
this->lb_last_line_offset = offset;
|
|
|
|
}
|
|
|
|
else if (offset >= this->lb_last_line_offset) {
|
|
|
|
this->lb_last_line_offset = offset + lv.lv_len;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
lv.lv_start = line_start;
|
|
|
|
offset += lv.lv_len;
|
|
|
|
|
|
|
|
retval = true;
|
|
|
|
}
|
|
|
|
else {
|
|
|
|
request_size += DEFAULT_INCREMENT;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (!retval && !this->fill_range(offset, request_size)) {
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
ensure(lv.lv_len <= this->lb_buffer_size);
|
|
|
|
ensure(!retval ||
|
|
|
|
(lv.lv_start >= this->lb_buffer &&
|
|
|
|
(lv.lv_start + lv.lv_len) <= (this->lb_buffer + this->lb_buffer_size)));
|
|
|
|
ensure(this->invariant());
|
|
|
|
|
|
|
|
return retval;
|
|
|
|
}
|
|
|
|
|
|
|
|
bool line_buffer::read_line(off_t &offset_inout, shared_buffer_ref &sbr)
|
|
|
|
throw (error)
|
|
|
|
{
|
|
|
|
line_value lv;
|
|
|
|
bool retval;
|
|
|
|
|
|
|
|
// Clear the incoming ref right away so that an invalidate
|
|
|
|
// does not cause a wasted malloc/copy.
|
|
|
|
sbr.disown();
|
|
|
|
if ((retval = this->read_line(offset_inout, lv))) {
|
|
|
|
sbr.share(this->lb_share_manager, lv.lv_start, lv.lv_len);
|
|
|
|
}
|
|
|
|
|
|
|
|
return retval;
|
|
|
|
}
|
|
|
|
|
|
|
|
bool line_buffer::read_range(off_t offset, size_t len, shared_buffer_ref &sbr)
|
|
|
|
throw (error)
|
|
|
|
{
|
|
|
|
char *line_start;
|
|
|
|
size_t avail;
|
|
|
|
|
|
|
|
sbr.disown();
|
|
|
|
|
|
|
|
if (this->lb_last_line_offset != -1 && offset > this->lb_last_line_offset) {
|
|
|
|
/*
|
|
|
|
* Don't return anything past the last known line. The caller needs
|
|
|
|
* to try reading at the offset of the last line again.
|
|
|
|
*/
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
this->fill_range(offset, len);
|
|
|
|
line_start = this->get_range(offset, avail);
|
|
|
|
|
|
|
|
sbr.share(this->lb_share_manager, line_start, len);
|
|
|
|
|
|
|
|
return true;
|
|
|
|
}
|