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MySQL 8.3.0
Source Code Documentation
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MySQL 8.3.0
Source Code Documentation
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Implements the large objects (LOB) module. More...
#include <my_dbug.h>#include "btr0pcur.h"#include "dict0mem.h"#include "page0page.h"#include "row0log.h"#include "univ.i"Go to the source code of this file.
Classes | |
| struct | lob::ref_mem_t |
| In memory representation of the LOB reference. More... | |
| struct | lob::ref_t |
| The struct 'lob::ref_t' represents an external field reference. More... | |
| class | lob::BtrContext |
| The B-tree context under which the LOB operation is done. More... | |
| struct | lob::InsertContext |
| The context for a LOB operation. More... | |
| struct | lob::blob_page_info_t |
| Information about data stored in one BLOB page. More... | |
| struct | lob::blob_dir_t |
| The in-memory blob directory. More... | |
| struct | lob::ReadContext |
| The context information for reading a single BLOB. More... | |
| struct | lob::zReader |
| Fetch compressed BLOB. More... | |
| struct | lob::Reader |
| Fetch uncompressed BLOB. More... | |
| struct | lob::DeleteContext |
| The context information when the delete operation on LOB is taking place. More... | |
Namespaces | |
| namespace | lob |
| Provides the large objects (LOB) module. | |
Typedefs | |
| typedef std::map< page_no_t, buf_block_t * > | BlockCache |
Enumerations | |
| enum | lob::opcode { lob::OPCODE_INSERT = 0 , lob::OPCODE_INSERT_UPDATE , lob::OPCODE_UPDATE , lob::OPCODE_INSERT_BULK , lob::OPCODE_UNKNOWN } |
| LOB operation code for btr_store_big_rec_extern_fields(). More... | |
Functions | |
| std::ostream & | lob::operator<< (std::ostream &out, const ref_t &obj) |
| Overload the global output stream operator to easily print the lob::ref_t object into the output stream. More... | |
| dberr_t | lob::btr_store_big_rec_extern_fields (trx_t *trx, btr_pcur_t *pcur, const upd_t *upd, ulint *offsets, const big_rec_t *big_rec_vec, mtr_t *btr_mtr, opcode op) |
| Stores the fields in big_rec_vec to the tablespace and puts pointers to them in rec. More... | |
| byte * | lob::btr_rec_copy_externally_stored_field_func (trx_t *trx, const dict_index_t *index, const rec_t *rec, const ulint *offsets, const page_size_t &page_size, ulint no, ulint *len, size_t *lob_version, bool is_sdi, mem_heap_t *heap, bool is_rebuilt) |
| Copies an externally stored field of a record to mem heap. More... | |
| static byte * | lob::btr_rec_copy_externally_stored_field (trx_t *trx, const dict_index_t *index, const rec_t *rec, const ulint *offsets, const page_size_t &page_size, ulint no, ulint *len, size_t *ver, bool is_sdi, mem_heap_t *heap) |
| ulint | lob::btr_rec_get_field_ref_offs (const dict_index_t *index, const ulint *offsets, ulint n) |
| Gets the offset of the pointer to the externally stored part of a field. More... | |
| static const byte * | lob::btr_rec_get_field_ref (const dict_index_t *index, const byte *rec, const ulint *offsets, ulint n) |
| Gets a pointer to the externally stored part of a field. More... | |
| static byte * | lob::btr_rec_get_field_ref (const dict_index_t *index, byte *rec, const ulint *offsets, ulint n) |
| Gets a pointer to the externally stored part of a field. More... | |
| void | lob::blob_free (dict_index_t *index, buf_block_t *block, bool all, mtr_t *mtr) |
| Deallocate a buffer block that was reserved for a BLOB part. More... | |
| std::ostream & | lob::operator<< (std::ostream &out, const blob_page_info_t &obj) |
| std::ostream & | lob::operator<< (std::ostream &out, const blob_dir_t &obj) |
| Overloading the global output operator to print the blob_dir_t object into an output stream. More... | |
| bool | lob::btr_lob_op_is_update (opcode op) |
| Determine if an operation on off-page columns is an update. More... | |
| ulint | lob::btr_copy_externally_stored_field_prefix_func (trx_t *trx, const dict_index_t *index, byte *buf, ulint len, const page_size_t &page_size, const byte *data, bool is_sdi, ulint local_len) |
| Copies the prefix of an externally stored field of a record. More... | |
| byte * | lob::btr_copy_externally_stored_field_func (trx_t *trx, const dict_index_t *index, ulint *len, size_t *lob_version, const byte *data, const page_size_t &page_size, ulint local_len, bool is_sdi, mem_heap_t *heap) |
| Copies an externally stored field of a record to mem heap. More... | |
| static ulint | lob::btr_copy_externally_stored_field_prefix (trx_t *trx, const dict_index_t *index, byte *buf, ulint len, const page_size_t &page_size, const byte *data, bool is_sdi, ulint local_len) |
| static byte * | lob::btr_copy_externally_stored_field (trx_t *trx, const dict_index_t *index, ulint *len, size_t *ver, const byte *data, const page_size_t &page_size, ulint local_len, bool is_sdi, mem_heap_t *heap) |
| ulint | lob::btr_rec_get_externally_stored_len (const dict_index_t *index, const rec_t *rec, const ulint *offsets) |
| Gets the externally stored size of a record, in units of a database page. More... | |
| void | lob::purge (lob::DeleteContext *ctx, dict_index_t *index, trx_id_t trxid, undo_no_t undo_no, ulint rec_type, const upd_field_t *uf, purge_node_t *node) |
| Purge an LOB (either of compressed or uncompressed). More... | |
| dberr_t | lob::update (InsertContext &ctx, trx_t *trx, dict_index_t *index, const upd_t *upd, ulint field_no, ref_t blobref) |
| Update a portion of the given LOB. More... | |
| dberr_t | lob::z_update (InsertContext &ctx, trx_t *trx, dict_index_t *index, const upd_t *upd, ulint field_no, ref_t blobref) |
| Update a portion of the given LOB. More... | |
| void | lob::print (trx_t *trx, dict_index_t *index, std::ostream &out, ref_t ref, bool fatal) |
| Print information about the given LOB. More... | |
| void | lob::z_import (const dict_index_t *index, byte *field_ref, trx_id_t trx_id) |
| Import the given LOB. More... | |
| void | lob::import (const dict_index_t *index, byte *field_ref, trx_id_t trx_id) |
| Import the given LOB. More... | |
| bool | lob::rec_check_lobref_space_id (dict_index_t *index, const rec_t *rec, const ulint *offsets) |
| Check if all the LOB references in the given clustered index record has valid space_id in it. More... | |
| dberr_t | lob::mark_not_partially_updatable (trx_t *trx, dict_index_t *index, const upd_t *update, const mtr_t *btr_mtr) |
| Mark an LOB that it is not partially updatable anymore. More... | |
Variables | |
| const ulint | lob::MAX_SIZE = UINT32_MAX |
| The maximum size possible for an LOB. More... | |
| constexpr uint32_t | lob::KB128 = 128 * 1024 |
| The compressed LOB is stored as a collection of zlib streams. More... | |
| constexpr uint32_t | lob::Z_CHUNK_SIZE = KB128 |
| const ulint | lob::BTR_EXTERN_SPACE_ID = 0 |
| The reference in a field for which data is stored on a different page. More... | |
| const ulint | lob::BTR_EXTERN_PAGE_NO = 4 |
| page number where stored More... | |
| const ulint | lob::BTR_EXTERN_OFFSET = 8 |
| offset of BLOB header on that page More... | |
| const ulint | lob::BTR_EXTERN_VERSION = BTR_EXTERN_OFFSET |
| Version number of LOB (LOB in new format) More... | |
| const ulint | lob::BTR_EXTERN_LEN = 12 |
| 8 bytes containing the length of the externally stored part of the LOB. More... | |
| const ulint | lob::BTR_EXTERN_OWNER_FLAG = 128UL |
| The most significant bit of BTR_EXTERN_LEN (i.e., the most significant bit of the byte at smallest address) is set to 1 if this field does not 'own' the externally stored field; only the owner field is allowed to free the field in purge! More... | |
| const ulint | lob::BTR_EXTERN_INHERITED_FLAG = 64UL |
| If the second most significant bit of BTR_EXTERN_LEN (i.e., the second most significant bit of the byte at smallest address) is 1 then it means that the externally stored field was inherited from an earlier version of the row. More... | |
| const ulint | lob::BTR_EXTERN_BEING_MODIFIED_FLAG = 32UL |
| If the 3rd most significant bit of BTR_EXTERN_LEN is 1, then it means that the externally stored field is currently being modified. More... | |
| const ulint | lob::LOB_HDR_PART_LEN = 0 |
| The structure of uncompressed LOB page header. More... | |
| const ulint | lob::LOB_HDR_NEXT_PAGE_NO = 4 |
| Offset within header of next BLOB part page no. More... | |
| const ulint | lob::LOB_HDR_SIZE = 8 |
| Size of an uncompressed LOB page header, in bytes. More... | |
| const uint | lob::ZLOB_PAGE_DATA = FIL_PAGE_DATA |
| Start of the data on an LOB page. More... | |
| const byte | lob::field_ref_almost_zero [FIELD_REF_SIZE] |
| A BLOB field reference has all the bits set to zero, except the "being
modified" bit. More... | |
Implements the large objects (LOB) module.
InnoDB supports large objects (LOB). Previously, the LOB was called as externally stored fields. A large object contains a singly linked list of database pages, aka LOB pages. A reference to the first LOB page is stored along with the clustered index record. This reference is called the LOB reference (lob::ref_t). A single clustered index record can have many LOB references. Secondary indexes cannot have LOB references.
There are two types of LOB - compressed and uncompressed.
The main operations implemented for LOB are - INSERT, DELETE and FETCH. To carry out these main operations the following classes are provided.
Inserter - for inserting uncompressed LOB data. zInserter - for inserting compressed LOB data. BaseInserter - a base class containing common state and functions useful for both Inserter and zInserter. Inserter and zInserter derives from this base class. Reader - for reading uncompressed LOB data. zReader - for reading compressed LOB data. Deleter - for deleting both compressed and uncompressed LOB data.
For each main operation, the context information is identified separately. They are as follows:
InsertContext - context information for doing insert of LOB. DeleteContext - context information for doing delete of LOB. ReadContext - context information for doing fetch of LOB. `
| typedef std::map<page_no_t, buf_block_t *> BlockCache |
1.9.2