/* Copyright (C) 2003 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; either version 2 of the License, or (at your option) any later version. 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 */ /* Make sure to look at ha_tina.h for more details. First off, this is a play thing for me, there are a number of things wrong with it: *) It was designed for csv and therefor its performance is highly questionable. *) Indexes have not been implemented. This is because the files can be traded in and out of the table directory without having to worry about rebuilding anything. *) NULLs and "" are treated equally (like a spreadsheet). *) There was in the beginning no point to anyone seeing this other then me, so there is a good chance that I haven't quite documented it well. *) Less design, more "make it work" Now there are a few cool things with it: *) Errors can result in corrupted data files. *) Data files can be read by spreadsheets directly. TODO: *) Move to a block system for larger files *) Error recovery, its all there, just need to finish it *) Document how the chains work. -Brian */ #ifdef USE_PRAGMA_IMPLEMENTATION #pragma implementation // gcc: Class implementation #endif #include "mysql_priv.h" #ifdef HAVE_CSV_DB #include "ha_tina.h" #include <sys/mman.h> /* Stuff for shares */ pthread_mutex_t tina_mutex; static HASH tina_open_tables; static int tina_init= 0; /***************************************************************************** ** TINA tables *****************************************************************************/ /* Used for sorting chains. */ int sort_set (tina_set *a, tina_set *b) { return ( a->begin > b->begin ? 1 : ( a->begin < b->begin ? -1 : 0 ) ); } static byte* tina_get_key(TINA_SHARE *share,uint *length, my_bool not_used __attribute__((unused))) { *length=share->table_name_length; return (byte*) share->table_name; } /* Reloads the mmap file. */ int get_mmap(TINA_SHARE *share, int write) { DBUG_ENTER("ha_tina::get_mmap"); if (share->mapped_file && munmap(share->mapped_file, share->file_stat.st_size)) DBUG_RETURN(1); if (my_fstat(share->data_file, &share->file_stat, MYF(MY_WME)) == -1) DBUG_RETURN(1); if (share->file_stat.st_size) { if (write) share->mapped_file= (byte *)mmap(NULL, share->file_stat.st_size, PROT_READ|PROT_WRITE, MAP_SHARED, share->data_file, 0); else share->mapped_file= (byte *)mmap(NULL, share->file_stat.st_size, PROT_READ, MAP_PRIVATE, share->data_file, 0); if ((share->mapped_file ==(caddr_t)-1)) { /* Bad idea you think? See the problem is that nothing actually checks the return value of ::rnd_init(), so tossing an error is about it for us. Never going to happen right? :) */ my_message(errno, "Woops, blew up opening a mapped file", 0); DBUG_ASSERT(0); DBUG_RETURN(1); } } else share->mapped_file= NULL; DBUG_RETURN(0); } /* Simple lock controls. */ static TINA_SHARE *get_share(const char *table_name, TABLE *table) { TINA_SHARE *share; char *tmp_name; uint length; if (!tina_init) { /* Hijack a mutex for init'ing the storage engine */ pthread_mutex_lock(&LOCK_mysql_create_db); if (!tina_init) { tina_init++; VOID(pthread_mutex_init(&tina_mutex,MY_MUTEX_INIT_FAST)); (void) hash_init(&tina_open_tables,system_charset_info,32,0,0, (hash_get_key) tina_get_key,0,0); } pthread_mutex_unlock(&LOCK_mysql_create_db); } pthread_mutex_lock(&tina_mutex); length=(uint) strlen(table_name); if (!(share=(TINA_SHARE*) hash_search(&tina_open_tables, (byte*) table_name, length))) { char data_file_name[FN_REFLEN]; if (!my_multi_malloc(MYF(MY_WME | MY_ZEROFILL), &share, sizeof(*share), &tmp_name, length+1, NullS)) { pthread_mutex_unlock(&tina_mutex); return NULL; } share->use_count=0; share->table_name_length=length; share->table_name=tmp_name; strmov(share->table_name,table_name); fn_format(data_file_name, table_name, "", ".CSV",MY_REPLACE_EXT|MY_UNPACK_FILENAME); if (my_hash_insert(&tina_open_tables, (byte*) share)) goto error; thr_lock_init(&share->lock); pthread_mutex_init(&share->mutex,MY_MUTEX_INIT_FAST); if ((share->data_file= my_open(data_file_name, O_RDWR, MYF(0))) == -1) goto error2; /* We only use share->data_file for writing, so we scan to the end to append */ if (my_seek(share->data_file, 0, SEEK_END, MYF(0)) == MY_FILEPOS_ERROR) goto error2; share->mapped_file= NULL; // We don't know the state since we just allocated it if (get_mmap(share, 0) > 0) goto error3; } share->use_count++; pthread_mutex_unlock(&tina_mutex); return share; error3: my_close(share->data_file,MYF(0)); error2: thr_lock_delete(&share->lock); pthread_mutex_destroy(&share->mutex); error: pthread_mutex_unlock(&tina_mutex); my_free((gptr) share, MYF(0)); return NULL; } /* Free lock controls. */ static int free_share(TINA_SHARE *share) { DBUG_ENTER("ha_tina::free_share"); pthread_mutex_lock(&tina_mutex); int result_code= 0; if (!--share->use_count){ /* Drop the mapped file */ if (share->mapped_file) munmap(share->mapped_file, share->file_stat.st_size); result_code= my_close(share->data_file,MYF(0)); hash_delete(&tina_open_tables, (byte*) share); thr_lock_delete(&share->lock); pthread_mutex_destroy(&share->mutex); my_free((gptr) share, MYF(0)); } pthread_mutex_unlock(&tina_mutex); DBUG_RETURN(result_code); } /* Finds the end of a line. Currently only supports files written on a UNIX OS. */ byte * find_eoln(byte *data, off_t begin, off_t end) { for (off_t x= begin; x < end; x++) if (data[x] == '\n') return data + x; return 0; } /* Encode a buffer into the quoted format. */ int ha_tina::encode_quote(byte *buf) { char attribute_buffer[1024]; String attribute(attribute_buffer, sizeof(attribute_buffer), &my_charset_bin); buffer.length(0); for (Field **field=table->field ; *field ; field++) { const char *ptr; const char *end_ptr; (*field)->val_str(&attribute,&attribute); ptr= attribute.ptr(); end_ptr= attribute.length() + ptr; buffer.append('"'); while (ptr < end_ptr) { if (*ptr == '"') { buffer.append('\\'); buffer.append('"'); *ptr++; } else if (*ptr == '\r') { buffer.append('\\'); buffer.append('r'); *ptr++; } else if (*ptr == '\\') { buffer.append('\\'); buffer.append('\\'); *ptr++; } else if (*ptr == '\n') { buffer.append('\\'); buffer.append('n'); *ptr++; } else buffer.append(*ptr++); } buffer.append('"'); buffer.append(','); } // Remove the comma, add a line feed buffer.length(buffer.length() - 1); buffer.append('\n'); //buffer.replace(buffer.length(), 0, "\n", 1); return (buffer.length()); } /* chain_append() adds delete positions to the chain that we use to keep track of space. */ int ha_tina::chain_append() { if ( chain_ptr != chain && (chain_ptr -1)->end == current_position) (chain_ptr -1)->end= next_position; else { /* We set up for the next position */ if ((off_t)(chain_ptr - chain) == (chain_size -1)) { off_t location= chain_ptr - chain; chain_size += DEFAULT_CHAIN_LENGTH; if (chain_alloced) { /* Must cast since my_malloc unlike malloc doesn't have a void ptr */ if ((chain= (tina_set *)my_realloc((gptr)chain,chain_size,MYF(MY_WME))) == NULL) return -1; } else { tina_set *ptr= (tina_set *)my_malloc(chain_size * sizeof(tina_set),MYF(MY_WME)); memcpy(ptr, chain, DEFAULT_CHAIN_LENGTH * sizeof(tina_set)); chain= ptr; chain_alloced++; } chain_ptr= chain + location; } chain_ptr->begin= current_position; chain_ptr->end= next_position; chain_ptr++; } return 0; } /* Scans for a row. */ int ha_tina::find_current_row(byte *buf) { byte *mapped_ptr= (byte *)share->mapped_file + current_position; byte *end_ptr; DBUG_ENTER("ha_tina::find_current_row"); /* EOF should be counted as new line */ if ((end_ptr= find_eoln(share->mapped_file, current_position, share->file_stat.st_size)) == 0) DBUG_RETURN(HA_ERR_END_OF_FILE); for (Field **field=table->field ; *field ; field++) { buffer.length(0); mapped_ptr++; // Increment past the first quote for(;mapped_ptr != end_ptr; mapped_ptr++) { //Need to convert line feeds! if (*mapped_ptr == '"' && (((mapped_ptr[1] == ',') && (mapped_ptr[2] == '"')) || (mapped_ptr == end_ptr -1 ))) { mapped_ptr += 2; // Move past the , and the " break; } if (*mapped_ptr == '\\' && mapped_ptr != (end_ptr - 1)) { mapped_ptr++; if (*mapped_ptr == 'r') buffer.append('\r'); else if (*mapped_ptr == 'n' ) buffer.append('\n'); else if ((*mapped_ptr == '\\') || (*mapped_ptr == '"')) buffer.append(*mapped_ptr); else /* This could only happed with an externally created file */ { buffer.append('\\'); buffer.append(*mapped_ptr); } } else buffer.append(*mapped_ptr); } (*field)->store(buffer.ptr(), buffer.length(), system_charset_info); } next_position= (end_ptr - share->mapped_file)+1; /* Maybe use \N for null? */ memset(buf, 0, table->null_bytes); /* We do not implement nulls! */ DBUG_RETURN(0); } /* If frm_error() is called in table.cc this is called to find out what file extensions exist for this handler. */ const char **ha_tina::bas_ext() const { static const char *ext[]= { ".CSV", NullS }; return ext; } /* Open a database file. Keep in mind that tables are caches, so this will not be called for every request. Any sort of positions that need to be reset should be kept in the ::extra() call. */ int ha_tina::open(const char *name, int mode, uint test_if_locked) { DBUG_ENTER("ha_tina::open"); if (!(share= get_share(name, table))) DBUG_RETURN(1); thr_lock_data_init(&share->lock,&lock,NULL); ref_length=sizeof(off_t); DBUG_RETURN(0); } /* Close a database file. We remove ourselves from the shared strucutre. If it is empty we destroy it and free the mapped file. */ int ha_tina::close(void) { DBUG_ENTER("ha_tina::close"); DBUG_RETURN(free_share(share)); } /* This is an INSERT. At the moment this handler just seeks to the end of the file and appends the data. In an error case it really should just truncate to the original position (this is not done yet). */ int ha_tina::write_row(byte * buf) { int size; DBUG_ENTER("ha_tina::write_row"); statistic_increment(ha_write_count,&LOCK_status); if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT) table->timestamp_field->set_time(); size= encode_quote(buf); if (my_write(share->data_file, buffer.ptr(), size, MYF(MY_WME | MY_NABP))) DBUG_RETURN(-1); /* Ok, this is means that we will be doing potentially bad things during a bulk insert on some OS'es. What we need is a cleanup call for ::write_row that would let us fix up everything after the bulk insert. The archive handler does this with an extra mutx call, which might be a solution for this. */ if (get_mmap(share, 0) > 0) DBUG_RETURN(-1); DBUG_RETURN(0); } /* This is called for an update. Make sure you put in code to increment the auto increment, also update any timestamp data. Currently auto increment is not being fixed since autoincrements have yet to be added to this table handler. This will be called in a table scan right before the previous ::rnd_next() call. */ int ha_tina::update_row(const byte * old_data, byte * new_data) { int size; DBUG_ENTER("ha_tina::update_row"); statistic_increment(ha_update_count,&LOCK_status); if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_UPDATE) table->timestamp_field->set_time(); size= encode_quote(new_data); if (chain_append()) DBUG_RETURN(-1); if (my_write(share->data_file, buffer.ptr(), size, MYF(MY_WME | MY_NABP))) DBUG_RETURN(-1); DBUG_RETURN(0); } /* Deletes a row. First the database will find the row, and then call this method. In the case of a table scan, the previous call to this will be the ::rnd_next() that found this row. The exception to this is an ORDER BY. This will cause the table handler to walk the table noting the positions of all rows that match a query. The table will then be deleted/positioned based on the ORDER (so RANDOM, DESC, ASC). */ int ha_tina::delete_row(const byte * buf) { DBUG_ENTER("ha_tina::delete_row"); statistic_increment(ha_delete_count,&LOCK_status); if (chain_append()) DBUG_RETURN(-1); --records; DBUG_RETURN(0); } /* Fill buf with value from key. Simply this is used for a single index read with a key. */ int ha_tina::index_read(byte * buf, const byte * key, uint key_len __attribute__((unused)), enum ha_rkey_function find_flag __attribute__((unused))) { DBUG_ENTER("ha_tina::index_read"); DBUG_ASSERT(0); DBUG_RETURN(HA_ADMIN_NOT_IMPLEMENTED); } /* Fill buf with value from key. Simply this is used for a single index read with a key. Whatever the current key is we will use it. This is what will be in "index". */ int ha_tina::index_read_idx(byte * buf, uint index, const byte * key, uint key_len __attribute__((unused)), enum ha_rkey_function find_flag __attribute__((unused))) { DBUG_ENTER("ha_tina::index_read_idx"); DBUG_ASSERT(0); DBUG_RETURN(HA_ADMIN_NOT_IMPLEMENTED); } /* Read the next position in the index. */ int ha_tina::index_next(byte * buf) { DBUG_ENTER("ha_tina::index_next"); DBUG_ASSERT(0); DBUG_RETURN(HA_ADMIN_NOT_IMPLEMENTED); } /* Read the previous position in the index. */ int ha_tina::index_prev(byte * buf) { DBUG_ENTER("ha_tina::index_prev"); DBUG_ASSERT(0); DBUG_RETURN(HA_ADMIN_NOT_IMPLEMENTED); } /* Read the first position in the index */ int ha_tina::index_first(byte * buf) { DBUG_ENTER("ha_tina::index_first"); DBUG_ASSERT(0); DBUG_RETURN(HA_ADMIN_NOT_IMPLEMENTED); } /* Read the last position in the index With this we don't need to do a filesort() with index. We just read the last row and call previous. */ int ha_tina::index_last(byte * buf) { DBUG_ENTER("ha_tina::index_last"); DBUG_ASSERT(0); DBUG_RETURN(HA_ADMIN_NOT_IMPLEMENTED); } /* All table scans call this first. The order of a table scan is: ha_tina::store_lock ha_tina::external_lock ha_tina::info ha_tina::rnd_init ha_tina::extra ENUM HA_EXTRA_CACHE Cash record in HA_rrnd() ha_tina::rnd_next ha_tina::rnd_next ha_tina::rnd_next ha_tina::rnd_next ha_tina::rnd_next ha_tina::rnd_next ha_tina::rnd_next ha_tina::rnd_next ha_tina::rnd_next ha_tina::extra ENUM HA_EXTRA_NO_CACHE End cacheing of records (def) ha_tina::external_lock ha_tina::extra ENUM HA_EXTRA_RESET Reset database to after open Each call to ::rnd_next() represents a row returned in the can. When no more rows can be returned, rnd_next() returns a value of HA_ERR_END_OF_FILE. The ::info() call is just for the optimizer. */ int ha_tina::rnd_init(bool scan) { DBUG_ENTER("ha_tina::rnd_init"); current_position= next_position= 0; records= 0; chain_ptr= chain; #ifdef HAVE_MADVISE if (scan) (void)madvise(share->mapped_file,share->file_stat.st_size,MADV_SEQUENTIAL); #endif DBUG_RETURN(0); } /* ::rnd_next() does all the heavy lifting for a table scan. You will need to populate *buf with the correct field data. You can walk the field to determine at what position you should store the data (take a look at how ::find_current_row() works). The structure is something like: 0Foo Dog Friend The first offset is for the first attribute. All space before that is reserved for null count. Basically this works as a mask for which rows are nulled (compared to just empty). This table handler doesn't do nulls and does not know the difference between NULL and "". This is ok since this table handler is for spreadsheets and they don't know about them either :) */ int ha_tina::rnd_next(byte *buf) { DBUG_ENTER("ha_tina::rnd_next"); statistic_increment(ha_read_rnd_next_count,&LOCK_status); current_position= next_position; if (!share->mapped_file) DBUG_RETURN(HA_ERR_END_OF_FILE); if (HA_ERR_END_OF_FILE == find_current_row(buf) ) DBUG_RETURN(HA_ERR_END_OF_FILE); records++; DBUG_RETURN(0); } /* In the case of an order by rows will need to be sorted. ::position() is called after each call to ::rnd_next(), the data it stores is to a byte array. You can store this data via ha_store_ptr(). ref_length is a variable defined to the class that is the sizeof() of position being stored. In our case its just a position. Look at the bdb code if you want to see a case where something other then a number is stored. */ void ha_tina::position(const byte *record) { DBUG_ENTER("ha_tina::position"); ha_store_ptr(ref, ref_length, current_position); DBUG_VOID_RETURN; } /* Used to fetch a row from a posiion stored with ::position(). ha_get_ptr() retrieves the data for you. */ int ha_tina::rnd_pos(byte * buf, byte *pos) { DBUG_ENTER("ha_tina::rnd_pos"); statistic_increment(ha_read_rnd_count,&LOCK_status); current_position= ha_get_ptr(pos,ref_length); DBUG_RETURN(find_current_row(buf)); } /* ::info() is used to return information to the optimizer. Currently this table handler doesn't implement most of the fields really needed. SHOW also makes use of this data */ void ha_tina::info(uint flag) { DBUG_ENTER("ha_tina::info"); /* This is a lie, but you don't want the optimizer to see zero or 1 */ if (records < 2) records= 2; DBUG_VOID_RETURN; } /* Grab bag of flags that are sent to the able handler every so often. HA_EXTRA_RESET and HA_EXTRA_RESET_STATE are the most frequently called. You are not required to implement any of these. */ int ha_tina::extra(enum ha_extra_function operation) { DBUG_ENTER("ha_tina::extra"); DBUG_RETURN(0); } /* This is no longer used. */ int ha_tina::reset(void) { DBUG_ENTER("ha_tina::reset"); ha_tina::extra(HA_EXTRA_RESET); DBUG_RETURN(0); } /* Called after deletes, inserts, and updates. This is where we clean up all of the dead space we have collected while writing the file. */ int ha_tina::rnd_end() { DBUG_ENTER("ha_tina::rnd_end"); /* First position will be truncate position, second will be increment */ if ((chain_ptr - chain) > 0) { tina_set *ptr; off_t length; /* Setting up writable map, this will contain all of the data after the get_mmap call that we have added to the file. */ if (get_mmap(share, 1) > 0) DBUG_RETURN(-1); length= share->file_stat.st_size; /* The sort handles updates/deletes with random orders. It also sorts so that we move the final blocks to the beginning so that we move the smallest amount of data possible. */ qsort(chain, (size_t)(chain_ptr - chain), sizeof(tina_set), (qsort_cmp)sort_set); for (ptr= chain; ptr < chain_ptr; ptr++) { /* We peek a head to see if this is the last chain */ if (ptr+1 == chain_ptr) memmove(share->mapped_file + ptr->begin, share->mapped_file + ptr->end, length - (size_t)ptr->end); else memmove((caddr_t)share->mapped_file + ptr->begin, (caddr_t)share->mapped_file + ptr->end, (size_t)((ptr++)->begin - ptr->end)); length= length - (size_t)(ptr->end - ptr->begin); } /* Truncate the file to the new size */ if (my_chsize(share->data_file, length, 0, MYF(MY_WME))) DBUG_RETURN(-1); if (munmap(share->mapped_file, length)) DBUG_RETURN(-1); /* We set it to null so that get_mmap() won't try to unmap it */ share->mapped_file= NULL; if (get_mmap(share, 0) > 0) DBUG_RETURN(-1); } DBUG_RETURN(0); } /* Truncate table and others of its ilk call this. */ int ha_tina::delete_all_rows() { DBUG_ENTER("ha_tina::delete_all_rows"); int rc= my_chsize(share->data_file, 0, 0, MYF(MY_WME)); if (get_mmap(share, 0) > 0) DBUG_RETURN(-1); DBUG_RETURN(rc); } /* Always called by the start of a transaction (or by "lock tables"); */ int ha_tina::external_lock(THD *thd, int lock_type) { DBUG_ENTER("ha_tina::external_lock"); DBUG_RETURN(0); // No external locking } /* Called by the database to lock the table. Keep in mind that this is an internal lock. */ THR_LOCK_DATA **ha_tina::store_lock(THD *thd, THR_LOCK_DATA **to, enum thr_lock_type lock_type) { if (lock_type != TL_IGNORE && lock.type == TL_UNLOCK) lock.type=lock_type; *to++= &lock; return to; } /* Range optimizer calls this. I need to update the information on this. */ ha_rows ha_tina::records_in_range(int inx, const byte *start_key,uint start_key_len, enum ha_rkey_function start_search_flag, const byte *end_key,uint end_key_len, enum ha_rkey_function end_search_flag) { DBUG_ENTER("ha_tina::records_in_range "); DBUG_RETURN(records); // Good guess } /* Create a table. You do not want to leave the table open after a call to this (the database will call ::open() if it needs to). */ int ha_tina::create(const char *name, TABLE *table_arg, HA_CREATE_INFO *create_info) { char name_buff[FN_REFLEN]; File create_file; DBUG_ENTER("ha_tina::create"); if ((create_file= my_create(fn_format(name_buff,name,"",".CSV",MY_REPLACE_EXT|MY_UNPACK_FILENAME),0, O_RDWR | O_TRUNC,MYF(MY_WME))) < 0) DBUG_RETURN(-1); my_close(create_file,MYF(0)); DBUG_RETURN(0); } #endif /* enable CSV */