~drizzle-trunk/drizzle/development

/* Copyright (C) 2000 MySQL AB

   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; version 2 of the License.

   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

/*

  More functions to be used with IO_CACHE files

*/

#define MAP_TO_USE_RAID

#include "mysys_priv.h"

#include <m_string.h>

#include <stdarg.h>

#include <m_ctype.h>

/*

  Copy contents of an IO_CACHE to a file.

  SYNOPSIS

    my_b_copy_to_file()

    cache  IO_CACHE to copy from

    file   File to copy to

  DESCRIPTION

    Copy the contents of the cache to the file. The cache will be

    re-inited to a read cache and will read from the beginning of the

    cache.

    If a failure to write fully occurs, the cache is only copied

    partially.

  TODO

    Make this function solid by handling partial reads from the cache

    in a correct manner: it should be atomic.

  RETURN VALUE

    0  All OK

    1  An error occured

*/

int

my_b_copy_to_file(IO_CACHE *cache, FILE *file)

{

  size_t bytes_in_cache;

  DBUG_ENTER("my_b_copy_to_file");

  /* Reinit the cache to read from the beginning of the cache */

  if (reinit_io_cache(cache, READ_CACHE, 0L, FALSE, FALSE))

    DBUG_RETURN(1);

  bytes_in_cache= my_b_bytes_in_cache(cache);

  do

  {

    if (my_fwrite(file, cache->read_pos, bytes_in_cache,

                  MYF(MY_WME | MY_NABP)) == (size_t) -1)

      DBUG_RETURN(1);

    cache->read_pos= cache->read_end;

  } while ((bytes_in_cache= my_b_fill(cache)));

  DBUG_RETURN(0);

}

my_off_t my_b_append_tell(IO_CACHE* info)

{

  /*

    Prevent optimizer from putting res in a register when debugging

    we need this to be able to see the value of res when the assert fails

  */

  dbug_volatile my_off_t res; 

  /*

    We need to lock the append buffer mutex to keep flush_io_cache()

    from messing with the variables that we need in order to provide the

    answer to the question.

  */

#ifdef THREAD

  pthread_mutex_lock(&info->append_buffer_lock);

#endif

#ifndef DBUG_OFF

  /*

    Make sure EOF is where we think it is. Note that we cannot just use

    my_tell() because we have a reader thread that could have left the

    file offset in a non-EOF location

  */

  {

    volatile my_off_t save_pos;

    save_pos = my_tell(info->file,MYF(0));

    my_seek(info->file,(my_off_t)0,MY_SEEK_END,MYF(0));

    /*

      Save the value of my_tell in res so we can see it when studying coredump

    */

    DBUG_ASSERT(info->end_of_file - (info->append_read_pos-info->write_buffer)

		== (res=my_tell(info->file,MYF(0))));

    my_seek(info->file,save_pos,MY_SEEK_SET,MYF(0));

  }

#endif  

  res = info->end_of_file + (info->write_pos-info->append_read_pos);

#ifdef THREAD

  pthread_mutex_unlock(&info->append_buffer_lock);

#endif

  return res;

}

my_off_t my_b_safe_tell(IO_CACHE *info)

{

  if (unlikely(info->type == SEQ_READ_APPEND))

    return my_b_append_tell(info);

  return my_b_tell(info);

}

/*

  Make next read happen at the given position

  For write cache, make next write happen at the given position

*/

void my_b_seek(IO_CACHE *info,my_off_t pos)

{

  my_off_t offset;

  DBUG_ENTER("my_b_seek");

  DBUG_PRINT("enter",("pos: %lu", (ulong) pos));

  /*

    TODO:

       Verify that it is OK to do seek in the non-append

       area in SEQ_READ_APPEND cache

     a) see if this always works

     b) see if there is a better way to make it work

  */

  if (info->type == SEQ_READ_APPEND)

    VOID(flush_io_cache(info));

  offset=(pos - info->pos_in_file);

  if (info->type == READ_CACHE || info->type == SEQ_READ_APPEND)

  {

    /* TODO: explain why this works if pos < info->pos_in_file */

    if ((ulonglong) offset < (ulonglong) (info->read_end - info->buffer))

    {

      /* The read is in the current buffer; Reuse it */

      info->read_pos = info->buffer + offset;

      DBUG_VOID_RETURN;

    }

    else

    {

      /* Force a new read on next my_b_read */

      info->read_pos=info->read_end=info->buffer;

    }

  }

  else if (info->type == WRITE_CACHE)

  {

    /* If write is in current buffer, reuse it */

    if ((ulonglong) offset <

	(ulonglong) (info->write_end - info->write_buffer))

    {

      info->write_pos = info->write_buffer + offset;

      DBUG_VOID_RETURN;

    }

    VOID(flush_io_cache(info));

    /* Correct buffer end so that we write in increments of IO_SIZE */

    info->write_end=(info->write_buffer+info->buffer_length-

		     (pos & (IO_SIZE-1)));

  }

  info->pos_in_file=pos;

  info->seek_not_done=1;

  DBUG_VOID_RETURN;

}

/*

  Fill buffer of the cache.

  NOTES

    This assumes that you have already used all characters in the CACHE,

    independent of the read_pos value!

  RETURN

  0  On error or EOF (info->error = -1 on error)

  #  Number of characters

*/

size_t my_b_fill(IO_CACHE *info)

{

  my_off_t pos_in_file=(info->pos_in_file+

			(size_t) (info->read_end - info->buffer));

  size_t diff_length, length, max_length;

  if (info->seek_not_done)

  {					/* File touched, do seek */

    if (my_seek(info->file,pos_in_file,MY_SEEK_SET,MYF(0)) ==

	MY_FILEPOS_ERROR)

    {

      info->error= 0;

      return 0;

    }

    info->seek_not_done=0;

  }

  diff_length=(size_t) (pos_in_file & (IO_SIZE-1));

  max_length=(info->read_length-diff_length);

  if (max_length >= (info->end_of_file - pos_in_file))

    max_length= (size_t) (info->end_of_file - pos_in_file);

  if (!max_length)

  {

    info->error= 0;

    return 0;					/* EOF */

  }

  if ((length= my_read(info->file,info->buffer,max_length,

                       info->myflags)) == (size_t) -1)

  {

    info->error= -1;

    return 0;

  }

  info->read_pos=info->buffer;

  info->read_end=info->buffer+length;

  info->pos_in_file=pos_in_file;

  return length;

}

/*

  Read a string ended by '\n' into a buffer of 'max_length' size.

  Returns number of characters read, 0 on error.

  last byte is set to '\0'

  If buffer is full then to[max_length-1] will be set to \0.

*/

size_t my_b_gets(IO_CACHE *info, char *to, size_t max_length)

{

  char *start = to;

  size_t length;

  max_length--;					/* Save place for end \0 */

  /* Calculate number of characters in buffer */

  if (!(length= my_b_bytes_in_cache(info)) &&

      !(length= my_b_fill(info)))

    return 0;

  for (;;)

  {

    uchar *pos, *end;

    if (length > max_length)

      length=max_length;

    for (pos=info->read_pos,end=pos+length ; pos < end ;)

    {

      if ((*to++ = *pos++) == '\n')

      {

	info->read_pos=pos;

	*to='\0';

	return (size_t) (to-start);

      }

    }

    if (!(max_length-=length))

    {

     /* Found enough charcters;  Return found string */

      info->read_pos=pos;

      *to='\0';

      return (size_t) (to-start);

    }

    if (!(length=my_b_fill(info)))

      return 0;

  }

}

my_off_t my_b_filelength(IO_CACHE *info)

{

  if (info->type == WRITE_CACHE)

    return my_b_tell(info);

  info->seek_not_done= 1;

  return my_seek(info->file, 0L, MY_SEEK_END, MYF(0));

}

/*

  Simple printf version.  Supports '%s', '%d', '%u', "%ld" and "%lu"

  Used for logging in MySQL

  returns number of written character, or (size_t) -1 on error

*/

size_t my_b_printf(IO_CACHE *info, const char* fmt, ...)

{

  size_t result;

  va_list args;

  va_start(args,fmt);

  result=my_b_vprintf(info, fmt, args);

  va_end(args);

  return result;

}

size_t my_b_vprintf(IO_CACHE *info, const char* fmt, va_list args)

{

  size_t out_length= 0;

  uint minimum_width; /* as yet unimplemented */

  uint minimum_width_sign;

  uint precision; /* as yet unimplemented for anything but %b */

  my_bool is_zero_padded;

  /*

    Store the location of the beginning of a format directive, for the

    case where we learn we shouldn't have been parsing a format string

    at all, and we don't want to lose the flag/precision/width/size

    information.

   */

  const char* backtrack;

  for (; *fmt != '\0'; fmt++)

  {

    /* Copy everything until '%' or end of string */

    const char *start=fmt;

    size_t length;

    for (; (*fmt != '\0') && (*fmt != '%'); fmt++) ;

    length= (size_t) (fmt - start);

    out_length+=length;

    if (my_b_write(info, (const uchar*) start, length))

      goto err;

    if (*fmt == '\0')				/* End of format */

      return out_length;

    /* 

      By this point, *fmt must be a percent;  Keep track of this location and

      skip over the percent character. 

    */

    DBUG_ASSERT(*fmt == '%');

    backtrack= fmt;

    fmt++;

    is_zero_padded= FALSE;

    minimum_width_sign= 1;

    minimum_width= 0;

    precision= 0;

    /* Skip if max size is used (to be compatible with printf) */

process_flags:

    switch (*fmt)

    {

      case '-': 

        minimum_width_sign= -1; fmt++; goto process_flags;

      case '0':

        is_zero_padded= TRUE; fmt++; goto process_flags;

      case '#':

        /** @todo Implement "#" conversion flag. */  fmt++; goto process_flags;

      case ' ':

        /** @todo Implement " " conversion flag. */  fmt++; goto process_flags;

      case '+':

        /** @todo Implement "+" conversion flag. */  fmt++; goto process_flags;

    }

    if (*fmt == '*')

    {

      precision= (int) va_arg(args, int);

      fmt++;

    }

    else

    {

      while (my_isdigit(&my_charset_latin1, *fmt)) {

        minimum_width=(minimum_width * 10) + (*fmt - '0');

        fmt++;

      }

    }

    minimum_width*= minimum_width_sign;

    if (*fmt == '.')

    {

      fmt++;

      if (*fmt == '*') {

        precision= (int) va_arg(args, int);

        fmt++;

      }

      else

      {

        while (my_isdigit(&my_charset_latin1, *fmt)) {

          precision=(precision * 10) + (*fmt - '0');

          fmt++;

        }

      }

    }

    if (*fmt == 's')				/* String parameter */

    {

      register char *par = va_arg(args, char *);

      size_t length2 = strlen(par);

      /* TODO: implement precision */

      out_length+= length2;

      if (my_b_write(info, (uchar*) par, length2))

	goto err;

    }

    else if (*fmt == 'b')                       /* Sized buffer parameter, only precision makes sense */

    {

      char *par = va_arg(args, char *);

      out_length+= precision;

      if (my_b_write(info, (uchar*) par, precision))

        goto err;

    }

    else if (*fmt == 'd' || *fmt == 'u')	/* Integer parameter */

    {

      register int iarg;

      size_t length2;

      char buff[17];

      iarg = va_arg(args, int);

      if (*fmt == 'd')

	length2= (size_t) (int10_to_str((long) iarg,buff, -10) - buff);

      else

        length2= (uint) (int10_to_str((long) (uint) iarg,buff,10)- buff);

      /* minimum width padding */

      if (minimum_width > length2) 

      {

        char *buffz;

        buffz= my_alloca(minimum_width - length2);

        if (is_zero_padded)

          memset(buffz, '0', minimum_width - length2);

        else

          memset(buffz, ' ', minimum_width - length2);

        my_b_write(info, buffz, minimum_width - length2);

        my_afree(buffz);

      }

      out_length+= length2;

      if (my_b_write(info, (uchar*) buff, length2))

	goto err;

    }

    else if ((*fmt == 'l' && fmt[1] == 'd') || fmt[1] == 'u')

      /* long parameter */

    {

      register long iarg;

      size_t length2;

      char buff[17];

      iarg = va_arg(args, long);

      if (*++fmt == 'd')

	length2= (size_t) (int10_to_str(iarg,buff, -10) - buff);

      else

	length2= (size_t) (int10_to_str(iarg,buff,10)- buff);

      out_length+= length2;

      if (my_b_write(info, (uchar*) buff, length2))

	goto err;

    }

    else

    {

      /* %% or unknown code */

      if (my_b_write(info, (uchar*) backtrack, (size_t) (fmt-backtrack)))

        goto err;

      out_length+= fmt-backtrack;

    }

  }

  return out_length;

err:

  return (size_t) -1;

}