From 354bb40e75d94466e91fe6960523612c9d17ccfb Mon Sep 17 00:00:00 2001 From: Karen Arutyunov Date: Thu, 2 Nov 2017 23:11:29 +0300 Subject: Add implementation --- mysql/mysys/mf_iocache2.c | 514 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 514 insertions(+) create mode 100644 mysql/mysys/mf_iocache2.c (limited to 'mysql/mysys/mf_iocache2.c') diff --git a/mysql/mysys/mf_iocache2.c b/mysql/mysys/mf_iocache2.c new file mode 100644 index 0000000..c3505e6 --- /dev/null +++ b/mysql/mysys/mf_iocache2.c @@ -0,0 +1,514 @@ +/* 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 +#include +#include + +/* + 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; +} -- cgit v1.1