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().
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.
