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Diffstat (limited to 'mysql/mysys/mf_iocache2.c')
-rw-r--r--mysql/mysys/mf_iocache2.c514
1 files changed, 514 insertions, 0 deletions
diff --git a/mysql/mysys/mf_iocache2.c b/mysql/mysys/mf_iocache2.c
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+/* Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
+
+ 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
+
+/*
+ More functions to be used with IO_CACHE files
+*/
+
+#include "mysys_priv.h"
+#include "my_sys.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)));
+ if(cache->error == -1)
+ DBUG_RETURN(1);
+ DBUG_RETURN(0);
+}
+
+
+my_off_t my_b_append_tell(IO_CACHE* info)
+{
+ /*
+ Sometimes we want to make sure that the variable is not put into
+ a register in debugging mode so we can see its value in the core
+ */
+#ifndef DBUG_OFF
+# define dbug_volatile volatile
+#else
+# define dbug_volatile
+#endif
+
+ /*
+ 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.
+ */
+ mysql_mutex_lock(&info->append_buffer_lock);
+
+#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);
+ mysql_mutex_unlock(&info->append_buffer_lock);
+ 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 */
+ }
+ DBUG_EXECUTE_IF ("simulate_my_b_fill_error",
+ {DBUG_SET("+d,simulate_file_read_error");});
+ 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. Used for logging in MySQL.
+ Supports '%c', '%s', '%b', '%d', '%u', '%ld', '%lu' and '%llu'.
+ Returns number of written characters, or (size_t) -1 on error.
+
+ @param info The IO_CACHE to write to
+ @param fmt format string
+ @param ... variable list of arguments
+ @return number of bytes written, -1 if an error occurred
+*/
+
+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;
+}
+
+
+/**
+ Implementation of my_b_printf.
+
+ @param info The IO_CACHE to write to
+ @param fmt format string
+ @param args variable list of arguments
+ @return number of bytes written, -1 if an error occurred
+*/
+
+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 == '*')
+ {
+ minimum_width= (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 */
+ {
+ 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 == 'c') /* char type parameter */
+ {
+ char par[2];
+ par[0] = va_arg(args, int);
+ out_length++;
+ if (my_b_write(info, (uchar*) par, 1))
+ 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 */
+ {
+ int iarg;
+ size_t length2;
+ char buff[32];
+
+ 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);
+ if (my_b_write(info, buffz, minimum_width - length2))
+ {
+ goto err;
+ }
+ }
+
+ 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 */
+ {
+ long iarg;
+ size_t length2;
+ char buff[32];
+
+ 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 if (fmt[0] == 'l' && fmt[1] == 'l' && fmt[2] == 'u')
+ {
+ ulonglong iarg;
+ size_t length2;
+ char buff[32];
+
+ iarg = va_arg(args, ulonglong);
+ length2= (size_t) (longlong10_to_str(iarg, buff, 10) - buff);
+ out_length+= length2;
+ fmt+= 2;
+ 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;
+}
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