btr_root_raise_and_insert(): Because btr_page_set_level() must not
change level from non-zero to zero on compressed pages, invoke
btr_page_set_level() with page_zip==NULL and compress the entire
root page after creating it from the scratch.

btr_attach_half_pages(): Simplify the computation of lower_page_zip
and upper_page_zip.  Invoke btr_node_ptr_set_child_page_no() with
the correct page_zip.

page0page.h: Add __attribute__((const)) to functions testing for
infimum or supremum.

page_zip_dir_delete(): Note that the third parameter may be NULL.
Correct offset errors.

page_zip_available(): Use n_heap instead of n_recs.

page_zip_dir_find(), page_zip_dir_find_free(): Fix off-by-one error.

page_zip_fields_encode(), page_zip_fields_decode(): Encode and decode
index->n_nullable for non-leaf pages.

page_zip_apply_log(): Write REC_NEW_HEAP_NO before calling
rec_offs_make_valid().

page_zip_write_node_ptr(): Correct off-by-one error.

page_cur_search_with_match(): Make use of page_is_leaf().

page_dir_add_slots(): Replaced with page_dir_add_slot().  Use memmove().

before and after the operation.

buf_flush_init_for_writing(): Copy FIL_PAGE_LSN to the compressed page.

page_cur_insert_rec_low(): Add debug assertion.

page_zip_fixed_field_encode(), page_zip_fields_encode(),
page_zip_fields_decode(): Do not waste one bit when encoding quantities
larger than 127.

page_zip_apply_log(), page_zip_write_rec(): Decode and encode
heap_no >= 127 correctly.

page_zip_apply_log(): Correct an off-by-one error.

page_zip_write_rec(): Correct a debug assertion.
Encode heap_no as soon as possible.

row_upd_rec_in_place(), page_zip_write_rec(): Add parameter "index".

page_dir_set_n_heap(): Add a debug assertion that on compressed
pages, n_heap will always be incremented by one.  Improve code formatting.

page_zip_dir_add_slot(): New function, called from
page_cur_insert_rec_low() after page_mem_alloc_heap().

rec_set_n_owned_new(): Do not call page_zip_rec_set_owned()
on the supremum record.

rec_offs_make_valid(): Add debug assertions.

page_zip_dir_user_size(): Correct an off-by-one error in the debug assertion.

page_zip_apply_log(): Add parameter trx_id_col.  Skip trx_id and roll_ptr.

page_zip_decompress(): Simplify the handling of "storage" in the loop that
copies the uncompressed fields.

page_zip_write_rec(): Store trx_id and roll_ptr separately.

page_zip_write_trx_id(), page_zip_write_roll_ptr(): Fix off-by-one errors.

page_cur_insert_rec_low(): Call page_zip_dir_add_slot() after
page_mem_alloc_heap().  Remove some redundant assertions.
Pass page_zip to page_dir_split_slot().

rec_get_offsets_reverse(): Calculate extra_size correctly.

page_zip_apply_log(): Fix an off-by-one error in comparison.
Replace heap_status with hs where possible.
Increment the heap_no in heap_status correctly.

page_zip_decompress(): Eliminate the local variable "err".
Check for Z_STREAM_END only at the start of a record, so that
incomplete records will always be detected.

page_zip_write_rec(): Calculate the address of "storage" in the
same way as elsewhere.  Add TODO comments regarding the handling
of the uncompressed fields (BLOB pointers, trx_id, and roll_ptr).

btr_create(): page_zip_compress() returns FALSE on failure.

page_zip_write_header(): Write to page_zip->data[] instead of page_zip[].

buf_flush_init_for_writing(): Add parameter page_zip and set the fields
also in the header of the compressed page.

btr_cur_search_to_nth_level(): Add ut_ad() on page_zip_validate().

page_zip_compress(), page_zip_decompress(), page_zip_write_rec():
Note that the end marker of the modification log is 1 byte.

page_zip_find_heap_no(): Remove.

page_zip_apply_log(): Remove parameter "page".  Instead of a 2-byte offset
to the record, decode the heap number using a variable-length code.

page_zip_write_rec(): Check the range of heap_no with debug assertions.
Encode the heap number instead of an offset to the start of the record.

to page0zip.c.

function prototypes and comments.  These changes were accidentally
forgotten from revision 253.

operation succeeds.

page_zip_dir_set(): Remove, as the slots will be written to a temporary
buffer.

page_zip_dir_encode(): Replace page_zip with buf.  Make some assertions
more accurate.  Write the dense page directory to buf.

page_zip_compress(): Allocate a temporary buffer for the compressed page
except the page header.  Make some assertions more accurate.

page_zip_compress(), page_zip_decompress(): Remove 2 bytes of empty space
adjacent to the area reserved for storing uncompressed columns.

page_zip_decompress(): Free index and heap at the end of the function.
Do not write the index to the MLOG_ZIP_DECOMPRESS record, since it can be
decoded from the compressed page.

now that deletion of records on compressed pages is guaranteed to succeed.

on a compressed page.

page_zip_get_n_relocated(), page_zip_set_n_relocated(),
page_zip_get_relocated(): Remove.

page0zip.c, page0zip.ic: Remove all references to n_relocated.

page_cur_insert_rec_low(): On pages that are compressed,
never relocate records that are allocated from the free list.

page_zip_compress(): Add assertions !c_stream.avail_in where appropriate.
Add assertions on c_stream.next_in.  Correct malformed assertion on
externs > c_stream.next_in.  Note that there may be trailing garbage after
the last record.

page_zip_fields_decode(): Correctly decode variable-length fields having
maximum length greater than 255 bytes.

page_zip_decompress(): Remove the special treatment of the case !n_dense.
Replace the Z_NO_FLUSH argument of inflate() with Z_SYNC_FLUSH.
Treat Z_OK return value the same as Z_BUF_ERROR: always check avail_out.
After decompressing all records, decompress any trailing garbage.

page_cur_insert_rec_low(): Note that the relocation log
on the compressed page needs to reflect some changes of extra_size.

do not allow extra_size to decrease on compressed pages.

Split page_mem_alloc() to page_mem_alloc_free() and page_mem_alloc_heap().

page_cur_insert_rec_low(): Remove parameter "tuple".  Implement some of the
logic from page_mem_alloc().

page_cur_tuple_insert(): Convert the tuple to a record and calculate offsets.

page_zip_validate(): Assert that the page is in compact format.

Remove the declaration of the undefined function
page_zip_available_noninline().

Make page_zip_available() private to page0zip.c and page0zip.ic.

compressed pages.

btr_root_raise_and_insert(): Distinguish root_page_zip and new_page_zip.

btr_cur_set_ownership_of_extern_field(): Do not log the write on the
uncompressed page if it will be logged for page_zip.

lock_rec_insert_check_and_lock(), lock_sec_rec_modify_check_and_lock():
Update the max_trx_id field also on the compressed page.

mlog_write_ulint(): Add UNIV_UNLIKELY hints.  Remove trailing white space.

mlog_log_string(): Remove trailing white space.

rec_set_field_extern_bits(): Remove parameter mtr, as the write will either
occur in the heap, or it will be logged at a higher level.

recv_parse_or_apply_log_rec_body(),
page_zip_write_header(): Add log record type MLOG_ZIP_WRITE_HEADER.

page_header_set_field(): Pass mtr=NULL to page_zip_write_header().

page_header_reset_last_insert(): Pass mtr to page_zip_write_header().

btr_page_set_index_id(), btr_page_set_level(),
btr_page_set_next(), btr_page_set_prev(): Pass mtr to page_zip_write_header().

row_upd_rec_sys_fields(): Pass mtr=NULL to page_zip_write_trx_id() and
page_zip_write_roll_ptr(), since the write will be logged at a higher level.

page_zip_write_header(): Add parameter mtr.
page_zip_write_header_log(): New function.

Remove rec_set_nth_field_extern_bit().
Make rec_set_nth_field_extern_bit_old() static.
Rename rec_set_nth_field_extern_bit_new()
to rec_set_field_extern_bits_new() and make it static.

row_ins_index_entry_low(): Remove bogus TODO comment.

dict_mem_table_create(): Initialize table->zip.

btr0cur.c: Distinguish compressed BLOBs based on page_zip or table->zip.

Fix the way how btr_free_externally_stored_field() is called in purge.

btr_free_externally_stored_field(): Add parameter field_ref that points
directly to the BLOB reference.  Use rec, offsets, page_zip, and i
only for the page_zip_write_blob_ptr() call.

row_purge_upd_exist_or_extern(): Do not assume that the undo log contains
the entire record.  Only pass the BLOB reference to
btr_free_externally_stored_field().

btr_cur_pessimistic_insert(): Pass the "extern storage" flags to
btr_root_raise_and_insert() or btr_page_split_and_insert().

btr_copy_externally_stored_field(): Include local_len in the returned length.

btr_cur_optimistic_insert(): Replace page_cur_insert_rec_low()
with page_cur_tuple_insert().

btr_cur_pessimistic_update(): Add the columns of big_rec_vec to ext_vect,
so that the "extern storage" bits will be set correctly in
btr_cur_insert_if_possible().

This has not been extensively tested yet, because some other part of the
code breaks in "ibtestblob".

btr_free_page_low(): Add parameters "space" and "page_no", because they
are omitted from compressed BLOB pages.

btr0cur.c: Implement the compression and decompression of BLOB columns,
enabled at compile-time (#define ZIP_BLOB TRUE) for now.

btr_rec_free_externally_stored_fields(),
btr_copy_externally_stored_field(): Made static

mlog_log_string(): New function, split from mlog_write_string(), allows
to avoid a dummy memcpy() of compressed BLOB pages.

flag of records.  The flags may only be updated in heap-allocated
copies of records.

btr_root_raise_and_insert(),
btr_page_split_and_insert(),
btr_cur_insert_if_possible(),
btr_cur_optimistic_insert(),
btr_cur_pessimistic_insert(),
page_cur_tuple_insert(),
page_cur_insert_rec_low(): Add parameters "ext" and "n_ext".

dtuple_convert_big_rec(): Make parameter "ext" const.

BLOB pointers, trx_id, and roll_ptr.

btr_empty(), btr_create(), page_create(): Add parameter "index", as some
index information will be encoded on the compressed page.

Define REC_NODE_PTR_SIZE as 4.

Allow btr_page_reorganize() and btr_page_reorganize_low() to fail.

Define the error code DB_ZIP_OVERFLOW.

Make row_ins_index_entry_low() static.

page0zip: Encode the index, log reorganized records, and store uncompressed
fields separately from the compressed data stream.

that will require complete index information.

dict_create_index_step(): invoke dict_index_add_to_cache() before btr_create()

dict_index_remove_from_cache(): make public

dict_index_get_if_in_cache_low(): new function, for holding dict_sys->mutex

buf_flush_init_for_writing(): remove the temporary hook to page_zip_compress()

page_create(): add temporary hook to page_zip_compress()

buf_flush_init_for_writing(): The reported dense page directory size was
4 bytes too much.  Subtract 2 (infimum and supremum) from n_heap.

page_zip_decompress(): When decompressing the last user record, only set
heap_no and the status bits if there is data to decode, i.e., there
are user records on the page.

buf_flush_init_for_writing(): Improve the diagnostics and make the
condition for skipping pages accurate.

univ.i: Introduce UNIV_ZIP_DEBUG for enabling some page_zip_validate() tests.

page0zip.h, page0zip.c: Define and use page_zip_validate() in
page_zip_compress() and page_zip_write() if UNIV_ZIP_DEBUG or UNIV_DEBUG
is defined.