source: libwandio/iow-lzo.c @ e4eff86

/*
 * This file is part of libtrace
 *
 * Copyright (c) 2007,2008,2009,2010 The University of Waikato, Hamilton, 
 * New Zealand.
 *
 * Authors: Perry Lorier
 *          Shane Alcock 
 *          
 * All rights reserved.
 *
 * This code has been developed by the University of Waikato WAND 
 * research group. For further information please see http://www.wand.net.nz/
 *
 * libtrace 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.
 *
 * libtrace 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 libtrace; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * $Id: iow-lzo.c 1521 2010-02-08 22:21:16Z salcock $
 *
 */

/* This writes out lzo files in the same format as lzop does.  It's not as
 * flexible as lzop in an attempt to try and create a very fast method for
 * writing data out.
 *
 * Data is written out in blocks, and the blocks are all compressed in seperate
 * independant threads (if possible), thus letting you use multicore cpu's to
 * get compression for the absolute least amount of walltime while capturing.
 */

#include "config.h"
#include <lzo/lzo1x.h>
#include "wandio_internal.h"
#include "wandio.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <time.h> /* for mtime */
#include <errno.h>
#include <assert.h>
#include <inttypes.h>
#include <arpa/inet.h>
#include <pthread.h>
#include <unistd.h> /* for sysconf */
#include <stdbool.h>
#ifdef HAVE_SYS_PRCTL_H
#include <sys/prctl.h>
#endif


enum { 
        M_LZO1X_1     =     1,
        M_LZO1X_1_15  =     2,
        M_LZO1X_999   =     3,
        M_NRV1A       =  0x1a,
        M_NRV1B       =  0x1b,
        M_NRV2A       =  0x2a,
        M_NRV2B       =  0x2b,
        M_NRV2D       =  0x2d,
        M_ZLIB        =   128,
};

static const int F_OS_UNIX   = 0x03000000L;
static const int F_OS_MASK   = 0xff000000L;

static const int F_CS_NATIVE = 0x00000000L;
static const int F_CS_MASK   = 0x00f00000L;

static const int F_H_CRC32   = 0x00001000L;
static const int F_ADLER32_D = 0x00000001L;
static const int F_ADLER32_C = 0x00000002L;

/* popquiz! You throught "static const int" would be well constant didn't you?
 * You'd be wrong, you can't use them in places where the compiler needs a
 * constant, so you need to use an enum, since enums /are/ constant the compiler
 * will let you use them as such.  Sigh.
 */
enum { MAX_BLOCK_SIZE = 128*1024 }; /* lzop can only decompress blocks 
                                        this large */

/* According to lzop lzo can increase the data to this size, so save this
 * much space in our buffers 
 */
enum { MAX_BUFFER_SIZE = MAX_BLOCK_SIZE+MAX_BLOCK_SIZE/16+64+3 };

static const unsigned char lzop_magic[9] =
    { 0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a };


/* Libtrace IO module implementing a lzo writer */

enum err_t {
        ERR_OK  = 1,
        ERR_EOF = 0,
        ERR_ERROR = -1
};

const int ADLER32_INIT_VALUE = 1;
const int CRC32_INIT_VALUE = 0;

struct buffer_t {
        unsigned int offset;
        char buffer[MAX_BUFFER_SIZE];
};

struct lzothread_t {
        pthread_t thread;
        pthread_cond_t in_ready;
        pthread_cond_t out_ready;
        pthread_mutex_t mutex;
        bool closing;
        enum { EMPTY, WAITING, FULL } state;
        int num;
        struct buffer_t inbuf;
        struct buffer_t outbuf;
};

struct lzow_t {
        iow_t *child;
        enum err_t err;
        int threads;
        int next_thread;
        struct lzothread_t *thread;
};

extern iow_source_t lzo_wsource; 

#define DATA(iow) ((struct lzow_t *)((iow)->data))
#define min(a,b) ((a)<(b) ? (a) : (b))

static void write_buf(struct buffer_t *buffer,const void *data, size_t len)
{
        assert(buffer->offset + len < sizeof(buffer->buffer) && "Exceeded output buffer size in lzo compressor");
        memcpy(&buffer->buffer[buffer->offset], data, len);
        buffer->offset += len;
}

static void write32(struct buffer_t *buffer, uint32_t value)
{
        value = htonl(value);
        write_buf(buffer, &value, sizeof(value));
}

static void write16(struct buffer_t *buffer, uint16_t value)
{
        value = htons(value);
        write_buf(buffer, &value, sizeof(value));
}

static void write8(struct buffer_t *buffer, uint8_t value)
{
        write_buf(buffer, &value, sizeof(value));
}

static int lzo_wwrite_block(const char *buffer, off_t len, struct buffer_t *outbuf)
{
        char b2[MAX_BUFFER_SIZE];
        int err;
        lzo_uint dst_len;
        char scratch[LZO1X_1_MEM_COMPRESS];

        outbuf->offset=0;

        memset(scratch,0,sizeof(scratch));
        err=lzo1x_1_compress((void*)buffer, len, 
                        (void*)b2, &dst_len, 
                        scratch);

        switch(err) {
                case LZO_E_OK:
                        break;
                case LZO_E_ERROR:
                        return -EINVAL; /* WTF? */
                case LZO_E_OUT_OF_MEMORY:
                        return -ENOMEM; /* Uh oh */
                case LZO_E_NOT_COMPRESSIBLE:
                        return -EINVAL; /* Claimed not to be used, dunno what we'll do */
                case LZO_E_INPUT_OVERRUN:
                        return -EINVAL;  /* Can't happen on compress? */
                case LZO_E_OUTPUT_OVERRUN:
                        return -ENOMEM;
                case LZO_E_LOOKBEHIND_OVERRUN:
                        return -EINVAL;
                case LZO_E_EOF_NOT_FOUND:
                        return -ENOENT; /* Can't happen on compress? */
                case LZO_E_INPUT_NOT_CONSUMED:
                        return -EINVAL;
                case LZO_E_NOT_YET_IMPLEMENTED:
                        return -ENOSYS;
                default:
                        fprintf(stderr,"Unknown lzo error %d\n",err);
                        return -EINVAL;
        }

        write32(outbuf, len); /* Original length */
        write32(outbuf, min((uint32_t)len,(uint32_t)dst_len));
        /* CRC32 of the uncompressed buffer */
#if 0
        write32(outbuf, lzo_crc32(CRC32_INIT_VALUE, (void*)buffer, len));
#endif
        write32(outbuf, 
                lzo_adler32(ADLER32_INIT_VALUE, (const void*)buffer, len));
        write_buf(outbuf, b2, dst_len);

        /* Return the number of bytes compressed */
        return len;
}

/* There is one of these threads per core in a machine.  This compresses 
 * a block of data and returns it, the main thread tehn is responsible to
 * write these back out in the right order.
 */
static void *lzo_compress_thread(void *data)
{
        struct lzothread_t *me = (struct lzothread_t *)data;
        int err;
        char namebuf[17];

#ifdef PR_SET_NAME
        if (prctl(PR_GET_NAME, namebuf, 0,0,0) == 0) {
                char label[16];
                namebuf[16] = '\0'; /* Make sure it's NUL terminated */
                sprintf(label,"[lzo%d]",me->num);
                /* If the filename is too long, overwrite the last few bytes */
                if (strlen(namebuf)>=16-strlen(label)) {
                        strcpy(namebuf+15-strlen(label),label);
                }
                else {
                        strncat(namebuf," ",16);
                        strncat(namebuf,label,16);
                }
                prctl(PR_SET_NAME, namebuf, 0,0,0);
        }
#endif

        pthread_mutex_lock(&me->mutex);
        while (!me->closing) {
                while (me->state != WAITING) {
                        if (me->closing)
                                break;
                        pthread_cond_wait(&me->in_ready, &me->mutex);
                }
                if (me->closing)
                        break;

                err=lzo_wwrite_block(
                        me->inbuf.buffer, 
                        me->inbuf.offset,
                        &me->outbuf);

                if (err < 0)
                        break; 
                /* Make sure someone else hasn't clobbered us!*/
                assert(me->state == WAITING);
                me->state = FULL;
                pthread_cond_signal(&me->out_ready);
        }
        pthread_mutex_unlock(&me->mutex);

        return NULL;
}

iow_t *lzo_wopen(iow_t *child, int compress_level)
{
        const int opt_filter = 0;
        int flags;
        iow_t *iow;
        struct buffer_t buffer;
        buffer.offset=0;
        int i;

        if (!child)
                return NULL;

        if (lzo_init() != LZO_E_OK) {
                /* Fail */
                return NULL;
        }

        /* Compress level is useless for LZO, but getting UNUSED into here
         * is more trouble than it is worth so this check will at least
         * stop us from getting warnings about it.
         */
        if (compress_level < 0)
                return NULL;

        iow = malloc(sizeof(iow_t));
        iow->source = &lzo_wsource;
        iow->data = malloc(sizeof(struct lzow_t));

        DATA(iow)->child = child;
        DATA(iow)->err = ERR_OK;

        flags = 0;
        flags |= F_OS_UNIX & F_OS_MASK; /* Operating System */
        flags |= F_CS_NATIVE & F_CS_MASK;       /* Character Set */
        flags |= F_ADLER32_D; /* We adler32 the uncompressed data */
        /* flags |= F_STDIN; */
        /* flags |= F_STDOUT */
        /* flags |= F_MULTIPART; */
        /* flags |= F_H_CRC32; */

        write_buf(&buffer, lzop_magic, sizeof(lzop_magic));
        write16(&buffer, 0x1010 &0xFFFF); /* version: pretend to be LZOP version 0x1010 from lzop's version.h */
        write16(&buffer, lzo_version() & 0xFFFF); /* libversion */
        write16(&buffer, opt_filter ? 0x0950 : 0x0940); /* version needed to extract */
        write8(&buffer, M_LZO1X_1);     /* method */
        write8(&buffer, 5); /* level */
        write32(&buffer, flags); /* flags */
        /* if (flags & F_H_FILTER) 
                write32(iow, opt_filter); 
        */ 
        write32(&buffer, 0x600); /* mode: We assume traces may be sensitive */
        write32(&buffer, time(NULL)); /* mtime */
        write32(&buffer, 0); /* GMTdiff */

        /* Length, filename */
        write8(&buffer, strlen("compresseddata"));
        write_buf(&buffer, "compresseddata",strlen("compresseddata"));

        if (flags & F_H_CRC32) {
                write32(&buffer, 
                        lzo_crc32(CRC32_INIT_VALUE, 
                                (const void*)buffer.buffer+sizeof(lzop_magic), 
                                buffer.offset-sizeof(lzop_magic)));
        }
        else {
                uint32_t chksum=lzo_adler32(
                        ADLER32_INIT_VALUE, 
                        (const void *)buffer.buffer+sizeof(lzop_magic), 
                        buffer.offset-sizeof(lzop_magic));
                write32(&buffer, chksum);
        }

        wandio_wwrite(DATA(iow)->child,
                buffer.buffer,
                buffer.offset);

        /* Set up the thread pool -- one thread per core */
        DATA(iow)->threads = min((uint32_t)sysconf(_SC_NPROCESSORS_ONLN),
                        use_threads);
        DATA(iow)->thread = malloc(
                        sizeof(struct lzothread_t) * DATA(iow)->threads);
        DATA(iow)->next_thread = 0;
        for(i=0; i<DATA(iow)->threads; ++i) {
                pthread_cond_init(&DATA(iow)->thread[i].in_ready, NULL);
                pthread_cond_init(&DATA(iow)->thread[i].out_ready, NULL);
                pthread_mutex_init(&DATA(iow)->thread[i].mutex, NULL);
                DATA(iow)->thread[i].closing = false;
                DATA(iow)->thread[i].num = i;
                DATA(iow)->thread[i].state = EMPTY;
                DATA(iow)->thread[i].inbuf.offset = 0;

                pthread_create(&DATA(iow)->thread[i].thread, 
                                NULL,
                                lzo_compress_thread,
                                (void*)&DATA(iow)->thread[i]);
        }

        return iow;
}

static struct lzothread_t *get_next_thread(iow_t *iow)
{
        return &DATA(iow)->thread[DATA(iow)->next_thread];
}

static off_t lzo_wwrite(iow_t *iow, const char *buffer, off_t len)
{
        off_t ret = 0;
        while (len>0) {
                off_t size = len;
                off_t err;
                struct buffer_t outbuf;

                if (!DATA(iow)->threads) {
                        size = min(len, MAX_BLOCK_SIZE);
                        err=lzo_wwrite_block(buffer, size, &outbuf);
                        /* Flush the data out */
                        wandio_wwrite(DATA(iow)->child,
                                        outbuf.buffer,
                                        outbuf.offset);

                        if (err < 0) {/* Error */
                                if (ret == 0)
                                        return err;
                                /* If we've written some data, return that fact now, let them call back
                                 * and try and write more data, fail again then. 
                                 */
                                return ret;
                        }
                        else {
                                assert(err == size);
                                buffer += size;
                                len -= size;
                        }
                }
                else {
                        off_t space;

                        pthread_mutex_lock(&get_next_thread(iow)->mutex);
                        /* If this thread is still compressing, wait for it to finish */
                        while (get_next_thread(iow)->state == WAITING) {
                                pthread_cond_wait(
                                        &get_next_thread(iow)->out_ready, 
                                        &get_next_thread(iow)->mutex);
                        }

                        /* Flush any data out thats there */
                        if (get_next_thread(iow)->state == FULL) {
                                assert(get_next_thread(iow)->outbuf.offset 
                                                < sizeof(get_next_thread(iow)->outbuf.buffer));
                                wandio_wwrite(DATA(iow)->child,
                                                get_next_thread(iow)->outbuf.buffer,
                                                get_next_thread(iow)->outbuf.offset);
                                get_next_thread(iow)->state = EMPTY;
                                get_next_thread(iow)->inbuf.offset = 0;
                        }

                        assert(get_next_thread(iow)->state == EMPTY);

                        /* Figure out how much space we can copy into this buffer */
                        assert(MAX_BLOCK_SIZE <= sizeof(get_next_thread(iow)->inbuf.buffer));
                        space = MAX_BLOCK_SIZE-get_next_thread(iow)->inbuf.offset;
                        size = min(space, size);
                        assert(size>0);
                        assert(size <= MAX_BLOCK_SIZE);
                        assert(get_next_thread(iow)->inbuf.offset + size <= MAX_BLOCK_SIZE);

                        /* Move our data in */
                        memcpy(&get_next_thread(iow)->inbuf.buffer[get_next_thread(iow)->inbuf.offset], 
                                buffer, 
                                size);
                        get_next_thread(iow)->inbuf.offset += size;

                        /* If the buffer is now full Trigger the thread to start compressing this block,
                         * and move onto the next block.
                         */
                        if (get_next_thread(iow)->inbuf.offset >= sizeof(get_next_thread(iow)->inbuf.buffer)
                          ||get_next_thread(iow)->inbuf.offset >= MAX_BLOCK_SIZE) {
                                assert(get_next_thread(iow)->state == EMPTY);
                                get_next_thread(iow)->state = WAITING;
                                pthread_cond_signal(&get_next_thread(iow)->in_ready);

                                pthread_mutex_unlock(&get_next_thread(iow)->mutex);

                                DATA(iow)->next_thread = 
                                                (DATA(iow)->next_thread+1) % DATA(iow)->threads;
                        }
                        else 
                                pthread_mutex_unlock(&get_next_thread(iow)->mutex);

                        /* Update the lengths */
                        buffer += size;
                        len -= size;
                }
        }
        return len;
}

static void shutdown_thread(iow_t *iow, struct lzothread_t *thread)
{
        pthread_mutex_lock(&thread->mutex);

        /* If this buffer is empty it shouldn't have any data in it, we should have taken
         * care of that before.
         */
        /* thread->state == EMPTY implies thread->inbuf.offset == 0 */
        assert(!(thread->state == EMPTY) || thread->inbuf.offset == 0);

        while (thread->state == WAITING) {
                pthread_cond_wait(
                        &thread->out_ready,
                        &thread->mutex);
        }
        if (thread->state == FULL) {
                wandio_wwrite(DATA(iow)->child,
                                thread->outbuf.buffer,
                                thread->outbuf.offset);
                thread->state = EMPTY;
                thread->inbuf.offset = 0;
        }
        /* Now the thread should be empty, so ask it to shut down */
        assert(thread->state == EMPTY && thread->inbuf.offset == 0);
        thread->closing = true;
        pthread_cond_signal(&thread->in_ready);
        pthread_mutex_unlock(&thread->mutex);
        /* And wait for it to die */
        pthread_join(thread->thread,NULL);
}

static void lzo_wclose(iow_t *iow)
{
        const uint32_t zero = 0;
        int i;

        /* Flush the last buffer */
        pthread_mutex_lock(&get_next_thread(iow)->mutex);
        if (get_next_thread(iow)->state == EMPTY && get_next_thread(iow)->inbuf.offset != 0) {
                get_next_thread(iow)->state = WAITING;
                pthread_cond_signal(&get_next_thread(iow)->in_ready);
        }
        pthread_mutex_unlock(&get_next_thread(iow)->mutex);

        DATA(iow)->next_thread = 
                        (DATA(iow)->next_thread+1) % DATA(iow)->threads;

        /* Right, now we have to shutdown all our threads -- in order */
        for(i=DATA(iow)->next_thread; i<DATA(iow)->threads; ++i) {
                shutdown_thread(iow,&DATA(iow)->thread[i]);
        }
        for(i=0; i<DATA(iow)->next_thread; ++i) {
                shutdown_thread(iow,&DATA(iow)->thread[i]);
        }

        /* Write out an end of file marker */
        wandio_wwrite(DATA(iow)->child,
                &zero,
                sizeof(zero));

        /* And clean everything up */
        wandio_wdestroy(DATA(iow)->child);
        free(DATA(iow)->thread);
        free(iow->data);
        free(iow);
}

iow_source_t lzo_wsource = {
        "lzo",
        lzo_wwrite,
        lzo_wclose
};