From b829657046647c18c20ad2ee91935be2d59d40bc Mon Sep 17 00:00:00 2001
From: marko <Unknown>
Date: Wed, 10 May 2006 07:15:07 +0000
Subject: [PATCH] branches/zip: Fix bugs triggered by running out of space.

btr_root_raise_and_insert(): If page_copy_rec_list_end() fails,
copy the pages byte for byte.

page_zip_compress(): Ensure that the uncompressed storage area will
fit on the compressed page.
---
 btr/btr0btr.c   | 21 +++++++++++++++------
 page/page0zip.c | 16 +++++++++++-----
 2 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/btr/btr0btr.c b/btr/btr0btr.c
index 08c157a5d04..74416693219 100644
--- a/btr/btr0btr.c
+++ b/btr/btr0btr.c
@@ -1055,6 +1055,7 @@ btr_root_raise_and_insert(
 	page_zip_des_t*	new_page_zip;
 
 	root = btr_cur_get_page(cursor);
+	root_page_zip = buf_block_get_page_zip(buf_block_align(root));
 	tree = btr_cur_get_tree(cursor);
 
 	ut_ad(dict_tree_get_page(tree) == buf_frame_get_page_no(root));
@@ -1072,6 +1073,9 @@ btr_root_raise_and_insert(
 
 	new_page = btr_page_alloc(tree, 0, FSP_NO_DIR, level, mtr);
 	new_page_zip = buf_block_get_page_zip(buf_block_align(new_page));
+	ut_a(!new_page_zip == !root_page_zip);
+	ut_a(!new_page_zip || new_page_zip->size == root_page_zip->size);
+	ut_a(!root_page_zip || !root_page_zip->n_blobs);
 
 	btr_page_create(new_page, new_page_zip, tree, level, mtr);
 
@@ -1079,14 +1083,20 @@ btr_root_raise_and_insert(
 	btr_page_set_next(new_page, new_page_zip, FIL_NULL, mtr);
 	btr_page_set_prev(new_page, new_page_zip, FIL_NULL, mtr);
 
-	/* Move the records from root to the new page */
+	/* Copy the records from root to the new page one by one. */
 
 	if (UNIV_UNLIKELY(!page_copy_rec_list_end(new_page, new_page_zip,
 			page_get_infimum_rec(root), cursor->index, mtr))) {
-		/* This should always succeed, as new_page
-		is created from the scratch and receives
-		the records in sorted order. */
-		ut_error;
+		ut_a(new_page_zip);
+
+		/* Copy the pages byte for byte. This will succeed. */
+		buf_frame_copy(new_page, root);
+		memcpy(new_page_zip->data, root_page_zip->data,
+				new_page_zip->size);
+		new_page_zip->n_blobs = 0;
+		new_page_zip->m_start = root_page_zip->m_start;
+		new_page_zip->m_end = root_page_zip->m_end;
+		page_zip_compress_write_log(new_page_zip, new_page, mtr);
 	}
 
 	/* If this is a pessimistic insert which is actually done to
@@ -1114,7 +1124,6 @@ btr_root_raise_and_insert(
 				| REC_INFO_MIN_REC_FLAG);
 
 	/* Rebuild the root page to get free space */
-	root_page_zip = buf_block_get_page_zip(buf_block_align(root));
 	if (UNIV_LIKELY_NULL(root_page_zip)) {
 		page_create_zip(root, root_page_zip, cursor->index,
 				level + 1, mtr);
diff --git a/page/page0zip.c b/page/page0zip.c
index f131ff30c11..266ba993e69 100644
--- a/page/page0zip.c
+++ b/page/page0zip.c
@@ -560,6 +560,7 @@ page_zip_compress(
 	byte*		buf;	/* compressed payload of the page */
 	byte*		buf_end;/* end of buf */
 	ulint		n_dense;
+	ulint		slot_size;/* amount of uncompressed bytes per record */
 	const rec_t**	recs;	/* dense page directory, sorted by address */
 	mem_heap_t*	heap;
 	ulint		trx_id_col;
@@ -641,8 +642,8 @@ page_zip_compress(
 			ut_ad(trx_id_col > 0);
 			ut_ad(trx_id_col != ULINT_UNDEFINED);
 
-			c_stream.avail_out -= n_dense * (PAGE_ZIP_DIR_SLOT_SIZE
-				+ DATA_TRX_ID_LEN + DATA_ROLL_PTR_LEN);
+			slot_size = PAGE_ZIP_DIR_SLOT_SIZE
+					+ DATA_TRX_ID_LEN + DATA_ROLL_PTR_LEN;
 		} else {
 			/* Signal the absence of trx_id
 			in page_zip_fields_encode() */
@@ -650,14 +651,18 @@ page_zip_compress(
 					index, DATA_TRX_ID)
 					== ULINT_UNDEFINED);
 			trx_id_col = 0;
-			c_stream.avail_out -= n_dense * PAGE_ZIP_DIR_SLOT_SIZE;
+			slot_size = PAGE_ZIP_DIR_SLOT_SIZE;
 		}
 	} else {
-		c_stream.avail_out -= n_dense * (PAGE_ZIP_DIR_SLOT_SIZE
-				+ REC_NODE_PTR_SIZE);
+		slot_size = PAGE_ZIP_DIR_SLOT_SIZE + REC_NODE_PTR_SIZE;
 		trx_id_col = ULINT_UNDEFINED;
 	}
 
+	if (UNIV_UNLIKELY(c_stream.avail_out < n_dense * slot_size)) {
+		goto zlib_error;
+	}
+
+	c_stream.avail_out -= n_dense * slot_size;
 	c_stream.avail_in = page_zip_fields_encode(
 					n_fields, index, trx_id_col, fields);
 	c_stream.next_in = fields;
@@ -2951,6 +2956,7 @@ page_zip_compress_write_log(
 	mlog_close(mtr, log_ptr);
 
 	/* TODO: omit the unused bytes at page_zip->m_end */
+	/* TODO: omit some bytes at page header */
 	mlog_catenate_string(mtr, page_zip->data, page_zip->size);
 }