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.

Before the speedc test was interrupted, 121,765 B-tree pages were written.

buf_flush_init_for_writing(): Do not compress other than B-tree pages
outside the system tablespace.  Report non-B-tree pages.

page_zip_decompress(): Clear the unused heap space on the uncompressed page,
so that the whole buffer for the uncompressed page will be initialized and
page_zip_validate() will always succeed.

page_zip_dir_decode(): Correct the handling of the free list.

page_zip_set_extra_bytes(): Remove off-by-one error in the first loop.

page_zip_apply_log(): Replace parameter end with size, and let end=data+size.

page_zip_decompress(): Properly handle pages where the first user record has
more than REC_N_NEW_EXTRA_BYTES extra bytes.

page_delete_rec_list_end(): Remove page_zip_temp.  This operation will be
done completely in-place on page_zip.  If page_zip is specified, clear the
data bytes and the info and status bits of deleted records and clear the
removed directory slots.

page_dir_delete_slot(): Clear the last directory slot, which will be removed.

decompresses properly.

page_mem_free(): Adjust the temporary condition for zeroing data.

page_zip_compress(): Do not accept Z_STREAM_END from non-final deflate().
Tighten the assertion on c_stream.avail_in.

page_zip_dir_sort(): Note that the high bound is not inclusive.

page_zip_dir_decode(): Remove off-by-one error in page_zip_dir_sort() call.

page_zip_set_extra_bytes(): Add the termination condition that was forgotten
from the second for loop.  Simplify the code a little.

page_zip_decompress(): Do not accept Z_STREAM_END from non-final inflate().
Tighten the assertion on d_stream.avail_out.  Increment heap_status correctly.

A page with multiple records or deleted records still does not compress
or decompress properly.

buf_flush_init_for_writing(): Initialize block->page_zip properly so that all
assertions in page0zip can be enabled.

page_zip_decompress(): Note that corrupt data should not lead to assertions.

page_zip_dir_set(): Correct the interface.  Fix off-by-one error.
page_zip_dir_get(): Fix off-by-one error.

page0zip.c: Replace n_heap with n_dense and add comments about
the infimum and supremum records whenever we subtract 2 from heap_no.
Fix some programming errors.

buf0flu.c: Allocate the temporary buffer from buf_frame_alloc().

page_zip_simple_validate(): Do not assert page_zip->m_start >= PAGE_DATA.

page_zip_compress(): Replace some assertions with page_zip_simple_validate(),
and do not assert anything about page_zip->data contents.

page_zip_validate(): Do not compare the page trailer bytes.

page_zip_write(): Assert that the entire page headers match and
that page_zip->m_start >= PAGE_DATA.

Add a hook to buf0flu.c for testing compression and decompression.
TODO: adapt page_zip_write() calls.

Add function parameters and TODO comments regarding that.

page_dir_slot_set_n_owned(): Check page_zip_available().
page_dir_add_slots(): Add parameter page_zip.
btr_attach_half_pages(): Add parameter page_zip.
btr_node_ptr_set_child_page_no(): Add parameter page_zip.
Make comments about page_zip modification log usage more accurate.

page_dir_set_n_slots(): Add debug assertion that there will be enough space
available in the modification log of the compressed page.
page_trailer_get_len(): Simplify the formula.  Make more use of the function.

page_set_max_trx_id(), page_update_max_trx_id(): Add parameter page_zip.

Check that page_zip_decompress() is never called after modifying the
header or trailer of the compressed page, i.e., that page_zip_decompress()
will restore the uncompressed page as it was before the failed operation.

page_move_rec_list_start(): Restored.  Reorganize old page if compressed.
btr_page_split_and_insert(): Do left page splits.

buf_flush_buffered_writes(): Remove bogus assertion failure.

page_header_reset_last_insert(): Add page_zip parameter.
rec_get_next_ptr(): Return a pointer to the same page, or NULL.
page_dir_delete_slot(): Fix off-by-one errors.

Fix some (not all) bugs found by testing.

Fix bugs found during testing.

Add page_zip parameter to page_dir_slot_set_rec().
Improve the documentation of the page_zip parameters in page0page.
Add function page_trailer_get_len().

Slightly improve error handling.

Implement page_zip_write_header().
Add page_zip parameter to btr_page_set_ functions.
Allow page_copy_rec_list_end() to be called with invalid new_page_zip
if the page has been newly created.

Initial import of the zip-like compression of B-tree pages.