summaryrefslogtreecommitdiffstats
path: root/sql/discover.cc
diff options
context:
space:
mode:
Diffstat (limited to 'sql/discover.cc')
-rw-r--r--sql/discover.cc274
1 files changed, 274 insertions, 0 deletions
diff --git a/sql/discover.cc b/sql/discover.cc
new file mode 100644
index 00000000..20116935
--- /dev/null
+++ b/sql/discover.cc
@@ -0,0 +1,274 @@
+/* Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
+ Copyright (c) 2009, 2022, MariaDB Corporation.
+
+ 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 02110-1335 USA */
+
+
+/**
+ @file
+
+ @brief
+ Functions for discover of frm file from handler
+*/
+
+#include "mariadb.h"
+#include "sql_priv.h"
+#include "unireg.h"
+#include "discover.h"
+#include <my_dir.h>
+
+/**
+ Read the contents of a .frm file.
+
+ frmdata and len are set to 0 on error.
+
+ @param name path to table-file "db/name"
+ @param frmdata frm data
+ @param len length of the read frmdata
+
+ @retval
+ 0 ok
+ @retval
+ 1 Could not open file
+ @retval
+ 2 Could not stat file
+ @retval
+ 3 Could not allocate data for read. Could not read file
+*/
+
+int readfrm(const char *name, const uchar **frmdata, size_t *len)
+{
+ int error;
+ char index_file[FN_REFLEN];
+ File file;
+ size_t read_len;
+ uchar *read_data;
+ MY_STAT state;
+ DBUG_ENTER("readfrm");
+ DBUG_PRINT("enter",("name: '%s'",name));
+
+ *frmdata= NULL; // In case of errors
+ *len= 0;
+ error= 1;
+ if ((file= mysql_file_open(key_file_frm,
+ fn_format(index_file, name, "", reg_ext,
+ MY_UNPACK_FILENAME|MY_APPEND_EXT),
+ O_RDONLY | O_SHARE,
+ MYF(0))) < 0)
+ goto err_end;
+
+ // Get length of file
+ error= 2;
+ if (mysql_file_fstat(file, &state, MYF(0)))
+ goto err;
+ MSAN_STAT_WORKAROUND(&state);
+ read_len= (size_t)MY_MIN(FRM_MAX_SIZE, state.st_size); // safety
+
+ // Read whole frm file
+ error= 3;
+ if (!(read_data= (uchar*)my_malloc(key_memory_frm_string, read_len,
+ MYF(MY_WME))))
+ goto err;
+ if (mysql_file_read(file, read_data, read_len, MYF(MY_NABP)))
+ {
+ my_free(read_data);
+ goto err;
+ }
+
+ // Setup return data
+ *frmdata= (uchar*) read_data;
+ *len= read_len;
+ error= 0;
+
+ err:
+ (void) mysql_file_close(file, MYF(MY_WME));
+
+ err_end: /* Here when no file */
+ DBUG_RETURN (error);
+} /* readfrm */
+
+
+/*
+ Write the content of a frm data pointer to a frm or par file.
+
+ @param path full path to table-file "db/name.frm" or .par
+ @param db Database name. Only used for my_error()
+ @param table Table name. Only used for my_error()
+ @param data data to write to file
+ @param len length of the data
+
+ @retval
+ 0 ok
+ @retval
+ <> 0 Could not write file. In this case the file is not created
+*/
+
+int writefile(const char *path, const char *db, const char *table,
+ bool tmp_table, const uchar *data, size_t len)
+{
+ int error;
+ int create_flags= O_RDWR | O_TRUNC;
+ DBUG_ENTER("writefile");
+ DBUG_PRINT("enter",("name: '%s' len: %lu ",path, (ulong) len));
+
+ if (tmp_table)
+ create_flags|= O_EXCL | O_NOFOLLOW;
+
+ File file= mysql_file_create(key_file_frm, path,
+ CREATE_MODE, create_flags, MYF(0));
+
+ if (unlikely((error= file < 0)))
+ {
+ if (my_errno == ENOENT)
+ my_error(ER_BAD_DB_ERROR, MYF(0), db);
+ else
+ my_error(ER_CANT_CREATE_TABLE, MYF(0), db, table, my_errno);
+ }
+ else
+ {
+ error= (int)mysql_file_write(file, data, len, MYF(MY_WME | MY_NABP));
+
+ if (!error && !tmp_table && opt_sync_frm)
+ error= mysql_file_sync(file, MYF(MY_WME)) ||
+ my_sync_dir_by_file(path, MYF(MY_WME));
+
+ error|= mysql_file_close(file, MYF(MY_WME));
+ if (error)
+ my_delete(path, MYF(0));
+ }
+ DBUG_RETURN(error);
+} /* writefile */
+
+
+static inline void advance(FILEINFO* &from, FILEINFO* &to,
+ FILEINFO* cur, bool &skip)
+{
+ if (skip) // if not copying
+ from= cur; // just advance the start pointer
+ else // if copying
+ if (to == from) // but to the same place, not shifting the data
+ from= to= cur; // advance both pointers
+ else // otherwise
+ while (from < cur) // have to copy [from...cur) to [to...)
+ *to++ = *from++;
+ skip= false;
+}
+
+/**
+ Go through the directory listing looking for files with a specified
+ extension and add them to the result list
+
+ @details
+ This function may be called many times on the same directory listing
+ but with different extensions. To avoid discovering the same table twice,
+ whenever a table file is discovered, all files with the same name
+ (independently from the extensions) are removed from the list.
+
+ Example: the list contained
+ { "db.opt", "t1.MYD", "t1.MYI", "t1.frm", "t2.ARZ", "t3.ARZ", "t3.frm" }
+ on discovering all ".frm" files, tables "t1" and "t3" will be found,
+ and list will become
+ { "db.opt", "t2.ARZ" }
+ and now ".ARZ" discovery can discover the table "t2"
+
+ @note
+ This function assumes that the directory listing is sorted alphabetically.
+
+ @note Partitioning makes this more complicated. A partitioned table t1 might
+ have files, like t1.frm, t1#P#part1.ibd, t1#P#foo.ibd, etc.
+ That means we need to compare file names only up to the first '#' or '.'
+ whichever comes first.
+*/
+int extension_based_table_discovery(MY_DIR *dirp, const char *ext_meta,
+ handlerton::discovered_list *result)
+{
+ CHARSET_INFO *cs= character_set_filesystem;
+ size_t ext_meta_len= strlen(ext_meta);
+ FILEINFO *from, *to, *cur, *end;
+ bool skip= false;
+
+ from= to= cur= dirp->dir_entry;
+ end= cur + dirp->number_of_files;
+ while (cur < end)
+ {
+ char *octothorp= strchr(cur->name + 1, '#');
+ char *ext= strchr(octothorp ? octothorp : cur->name, FN_EXTCHAR);
+
+ if (ext)
+ {
+ size_t len= (octothorp ? octothorp : ext) - cur->name;
+ if (from != cur &&
+ (strlen(from->name) <= len ||
+ cs->strnncoll(from->name, len, cur->name, len) ||
+ (from->name[len] != FN_EXTCHAR && from->name[len] != '#')))
+ advance(from, to, cur, skip);
+
+ if (cs->strnncoll(ext, strlen(ext),
+ ext_meta, ext_meta_len) == 0)
+ {
+ *ext = 0;
+ if (result->add_file(cur->name))
+ return 1;
+ *ext = FN_EXTCHAR;
+ skip= true; // table discovered, skip all files with the same name
+ }
+ }
+ else
+ {
+ advance(from, to, cur, skip);
+ from++;
+ }
+
+ cur++;
+ }
+ advance(from, to, cur, skip);
+ dirp->number_of_files= to - dirp->dir_entry;
+ return 0;
+}
+
+/**
+ Simple, not reusable file-based table discovery
+
+ @details
+ simplified version of extension_based_table_discovery(), that does not
+ modify the list of files. It cannot be called many times for the same
+ directory listing, otherwise it'll produce duplicate results.
+*/
+int ext_table_discovery_simple(MY_DIR *dirp,
+ handlerton::discovered_list *result)
+{
+ CHARSET_INFO *cs= character_set_filesystem;
+ FILEINFO *cur, *end;
+
+ cur= dirp->dir_entry;
+ end= cur + dirp->number_of_files;
+ while (cur < end)
+ {
+ char *ext= strrchr(cur->name, FN_EXTCHAR);
+
+ if (ext)
+ {
+ if (cs->strnncoll(ext, strlen(ext),
+ reg_ext, reg_ext_length) == 0)
+ {
+ *ext = 0;
+ if (result->add_file(cur->name))
+ return 1;
+ }
+ }
+ cur++;
+ }
+ return 0;
+}
+