clean compressed pages (BUF_BLOCK_ZIP_PAGE).

introduced ib_longlong and %ll length specifier are not C89.)

row_ext_t: Change char* buf to byte* buf to avoid signedness warnings.

Change the type of all bit fields to unsigned.

rec_get_next_ptr(): Add (byte*) casts to avoid arithmetics on void*.

page_zip_decompress_clust(): Do not mix declarations and code.

free block in order to create two adjacent free blocks that can be
recombined.  Add some debug assertions.

buf_buddy_relocate(): New function: Try to relocate a free block.

buf_buddy_alloc_free_low() to buf_buddy_alloc_low().

Add parameter "split" for enabling splits.

compressed pages from the buffer pool.

Makefile.am: Add buf0buddy.h, buf0buddy.ic.

buf/Makefile.am: Add buf0buddy.c.

Introduce the constants BUF_BUDDY_LOW and BUF_BUDDY_SIZES.

buf_pool_t: Add zip_mutex and the lists zip_clean and zip_free[].

buf_page_get_mutex(): Return &buf_pool->zip_mutex instead of NULL.

buf_buddy_get_offset(), buf_buddy_get(), buf_buddy_get_slot(),
buf_buddy_alloc_free(), buf_buddy_alloc_free_low(): New functions.

and document the possible list memberships.

buf_LRU_block_remove_hashed_page() changes the state of the block.
This error was introduced in r1090.

to free_or_flush_list.  The list node pointers can be shared, because a
block can never be belong to both lists at the same time.

as the field will be read without mutex protection in buf_page_io_complete().

(state == BUF_BLOCK_ZIP_PAGE).  Make use of buf_page_in_file()
and buf_page_get_mutex().

buf_block_get_newest_modification(): Rename to
buf_page_get_newest_modification().

Add m_nonempty for facilitating the test in page_zip_alloc().  This
reduces the combined size of the bit-fields to 32 bits.  Thus,
sizeof(page_zip_des_t) == 2 machine words on 32-bit and wider systems.

LRU_position and possibly freed_page_clock.  All these fields are
protected by buf_pool->mutex rather than buf_page_get_mutex().

buf_page_set_accessed(): Add a mutex_own() assertion.

on a NULL pointer.  This error was introduced in r1082.

of the buffer pool from buf_block_t to buf_page_t.  Replace some buf_block_t*
parameters with buf_page_t*.  Add accessor functions.

decompression from page_zip_des_t to buf_page_t, because the fields
needed in compression are modified without holding the block mutex.
All writes to bit-fields sharing a machine word must be protected
by the same mutex or rw-lock.

buf_block_buf_fix_inc_func() to eliminate an #ifdef in every invocation.

to ut_uint64_align_down() and ut_uint64_align_up(), to reflect the rename
of ib_ulonglong to ib_uint64_t in r1085.

64 bits.  "long long" might be longer than 64 bits on some systems.

buf_block_t.  Move the fields "hash" and "file_page_was_freed" from
buf_block_t to buf_page_t.

buf_page_in_file(): New function, for checking block state in assertions.

was broken in r1066.

of the fields "freed_page_clock" and "old".

buf_page_t and page_zip_des_t.

storage size from 16 to 3 bits.

page_zip_get_size(), page_zip_set_size(): New functions.

Replace direct references to page_zip_des_t:size with calls to
buf_block_get_zip_size(), page_zip_get_size(), and page_zip_set_size().

for log sequence numbers, to replace dulint.

buf_block_get_state().

buf_block_init(), buf_page_init_for_backup_restore(): Assign
block->page.zip.state after invoking page_zip_des_init(&block->page).

introduced in r1057 are of the int type.

which should have been replaced in r1057.

threshold.

and uncompressed buffer pool pages.

buf_block_t: Replace page_zip, space, and offset with buf_page_t page.
Replace some integers with bit-fields.

enum buf_block_state: Rename to buf_page_state.  Add BUF_BLOCK_ZIP_PAGE.

page_zip_des_t: Add the field "state".  Make the integer fields bit-fields.

page_zip_copy(): Document which fields are copied.

buf_block_state_valid(): New macro for replacing the magic_n check

BUF_BLOCK_READY_FOR_USE to BUF_BLOCK_NOT_USED.

buf_block_get_space(), buf_block_get_page_no():
Remove ut_ad(block->buf_fix_count > 0), because since r1052
these functions are also used in low-level code.

buf_block_set_state(): New function.  Also checks the state transitions.

buf_block_set_file_page(): New function.