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Diffstat (limited to 'sql/rpl_utility.h')
| -rw-r--r-- | sql/rpl_utility.h | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/sql/rpl_utility.h b/sql/rpl_utility.h new file mode 100644 index 00000000000..8e2f4a7374f --- /dev/null +++ b/sql/rpl_utility.h @@ -0,0 +1,306 @@ +/* Copyright (C) 2006 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ + +#ifndef RPL_UTILITY_H +#define RPL_UTILITY_H + +#ifndef __cplusplus +#error "Don't include this C++ header file from a non-C++ file!" +#endif + +#include "mysql_priv.h" + +class Relay_log_info; + + +/** + A table definition from the master. + + The responsibilities of this class is: + - Extract and decode table definition data from the table map event + - Check if table definition in table map is compatible with table + definition on slave + + Currently, the only field type data available is an array of the + type operators that are present in the table map event. + + @todo Add type operands to this structure to allow detection of + difference between, e.g., BIT(5) and BIT(10). + */ + +class table_def +{ +public: + /** + Convenience declaration of the type of the field type data in a + table map event. + */ + typedef unsigned char field_type; + + /** + Constructor. + + @param types Array of types + @param size Number of elements in array 'types' + @param field_metadata Array of extra information about fields + @param metadata_size Size of the field_metadata array + @param null_bitmap The bitmap of fields that can be null + */ + table_def(field_type *types, ulong size, uchar *field_metadata, + int metadata_size, uchar *null_bitmap) + : m_size(size), m_type(0), m_field_metadata_size(metadata_size), + m_field_metadata(0), m_null_bits(0), m_memory(NULL) + { + m_memory= (uchar *)my_multi_malloc(MYF(MY_WME), + &m_type, size, + &m_field_metadata, + size * sizeof(uint16), + &m_null_bits, (size + 7) / 8, + NULL); + + bzero(m_field_metadata, size * sizeof(uint16)); + + if (m_type) + memcpy(m_type, types, size); + else + m_size= 0; + /* + Extract the data from the table map into the field metadata array + iff there is field metadata. The variable metadata_size will be + 0 if we are replicating from an older version server since no field + metadata was written to the table map. This can also happen if + there were no fields in the master that needed extra metadata. + */ + if (m_size && metadata_size) + { + int index= 0; + for (unsigned int i= 0; i < m_size; i++) + { + switch (m_type[i]) { + case MYSQL_TYPE_TINY_BLOB: + case MYSQL_TYPE_BLOB: + case MYSQL_TYPE_MEDIUM_BLOB: + case MYSQL_TYPE_LONG_BLOB: + case MYSQL_TYPE_DOUBLE: + case MYSQL_TYPE_FLOAT: + { + /* + These types store a single byte. + */ + m_field_metadata[i]= field_metadata[index]; + index++; + break; + } + case MYSQL_TYPE_SET: + case MYSQL_TYPE_ENUM: + case MYSQL_TYPE_STRING: + { + uint16 x= field_metadata[index++] << 8U; // real_type + x+= field_metadata[index++]; // pack or field length + m_field_metadata[i]= x; + break; + } + case MYSQL_TYPE_BIT: + { + uint16 x= field_metadata[index++]; + x = x + (field_metadata[index++] << 8U); + m_field_metadata[i]= x; + break; + } + case MYSQL_TYPE_VARCHAR: + { + /* + These types store two bytes. + */ + char *ptr= (char *)&field_metadata[index]; + m_field_metadata[i]= uint2korr(ptr); + index= index + 2; + break; + } + case MYSQL_TYPE_NEWDECIMAL: + { + uint16 x= field_metadata[index++] << 8U; // precision + x+= field_metadata[index++]; // decimals + m_field_metadata[i]= x; + break; + } + default: + m_field_metadata[i]= 0; + break; + } + } + } + if (m_size && null_bitmap) + memcpy(m_null_bits, null_bitmap, (m_size + 7) / 8); + } + + ~table_def() { + my_free(m_memory, MYF(0)); +#ifndef DBUG_OFF + m_type= 0; + m_size= 0; +#endif + } + + /** + Return the number of fields there is type data for. + + @return The number of fields that there is type data for. + */ + ulong size() const { return m_size; } + + + /* + Return a representation of the type data for one field. + + @param index Field index to return data for + + @return Will return a representation of the type data for field + <code>index</code>. Currently, only the type identifier is + returned. + */ + field_type type(ulong index) const + { + DBUG_ASSERT(index < m_size); + return m_type[index]; + } + + + /* + This function allows callers to get the extra field data from the + table map for a given field. If there is no metadata for that field + or there is no extra metadata at all, the function returns 0. + + The function returns the value for the field metadata for column at + position indicated by index. As mentioned, if the field was a type + that stores field metadata, that value is returned else zero (0) is + returned. This method is used in the unpack() methods of the + corresponding fields to properly extract the data from the binary log + in the event that the master's field is smaller than the slave. + */ + uint16 field_metadata(uint index) const + { + DBUG_ASSERT(index < m_size); + if (m_field_metadata_size) + return m_field_metadata[index]; + else + return 0; + } + + /* + This function returns whether the field on the master can be null. + This value is derived from field->maybe_null(). + */ + my_bool maybe_null(uint index) const + { + DBUG_ASSERT(index < m_size); + return ((m_null_bits[(index / 8)] & + (1 << (index % 8))) == (1 << (index %8))); + } + + /* + This function returns the field size in raw bytes based on the type + and the encoded field data from the master's raw data. This method can + be used for situations where the slave needs to skip a column (e.g., + WL#3915) or needs to advance the pointer for the fields in the raw + data from the master to a specific column. + */ + uint32 calc_field_size(uint col, uchar *master_data) const; + + /** + Decide if the table definition is compatible with a table. + + Compare the definition with a table to see if it is compatible + with it. + + A table definition is compatible with a table if: + - the columns types of the table definition is a (not + necessarily proper) prefix of the column type of the table, or + - the other way around + + @param rli Pointer to relay log info + @param table Pointer to table to compare with. + + @retval 1 if the table definition is not compatible with @c table + @retval 0 if the table definition is compatible with @c table + */ +#ifndef MYSQL_CLIENT + int compatible_with(Relay_log_info const *rli, TABLE *table) const; +#endif + +private: + ulong m_size; // Number of elements in the types array + field_type *m_type; // Array of type descriptors + uint m_field_metadata_size; + uint16 *m_field_metadata; + uchar *m_null_bits; + uchar *m_memory; +}; + + +#ifndef MYSQL_CLIENT +/** + Extend the normal table list with a few new fields needed by the + slave thread, but nowhere else. + */ +struct RPL_TABLE_LIST + : public TABLE_LIST +{ + bool m_tabledef_valid; + table_def m_tabledef; +}; + + +/* Anonymous namespace for template functions/classes */ +namespace { + + /* + Smart pointer that will automatically call my_afree (a macro) when + the pointer goes out of scope. This is used so that I do not have + to remember to call my_afree() before each return. There is no + overhead associated with this, since all functions are inline. + + I (Matz) would prefer to use the free function as a template + parameter, but that is not possible when the "function" is a + macro. + */ + template <class Obj> + class auto_afree_ptr + { + Obj* m_ptr; + public: + auto_afree_ptr(Obj* ptr) : m_ptr(ptr) { } + ~auto_afree_ptr() { if (m_ptr) my_afree(m_ptr); } + void assign(Obj* ptr) { + /* Only to be called if it hasn't been given a value before. */ + DBUG_ASSERT(m_ptr == NULL); + m_ptr= ptr; + } + Obj* get() { return m_ptr; } + }; + +} +#endif + +#define DBUG_PRINT_BITSET(N,FRM,BS) \ + do { \ + char buf[256]; \ + for (uint i = 0 ; i < (BS)->n_bits ; ++i) \ + buf[i] = bitmap_is_set((BS), i) ? '1' : '0'; \ + buf[(BS)->n_bits] = '\0'; \ + DBUG_PRINT((N), ((FRM), buf)); \ + } while (0) + +#endif /* RPL_UTILITY_H */ |