Exemplo n.º 1
0
/*
 * __wt_addr_string --
 *	Load a buffer with a printable, nul-terminated representation of an
 * address.
 */
const char *
__wt_addr_string(
    WT_SESSION_IMPL *session, WT_ITEM *buf, const uint8_t *addr, uint32_t size)
{
	WT_BM *bm;

	bm = S2BT(session)->bm;

	if (addr == NULL) {
		buf->data = "[NoAddr]";
		buf->size = WT_STORE_SIZE(strlen("[NoAddr]"));
	} else if (bm->addr_string(bm, session, buf, addr, size) != 0) {
		buf->data = "[Error]";
		buf->size = WT_STORE_SIZE(strlen("[Error]"));
	}
	return (buf->data);
}
Exemplo n.º 2
0
/*
 * __wt_addr_string --
 *	Load a buffer with a printable, nul-terminated representation of an
 * address.
 */
const char *
__wt_addr_string(WT_SESSION_IMPL *session,
    const uint8_t *addr, size_t addr_size, WT_ITEM *buf)
{
	WT_BM *bm;
	WT_BTREE *btree;

	btree = S2BT_SAFE(session);

	if (addr == NULL) {
		buf->data = "[NoAddr]";
		buf->size = strlen("[NoAddr]");
	} else if (btree == NULL || (bm = btree->bm) == NULL ||
	    bm->addr_string(bm, session, buf, addr, addr_size) != 0) {
		buf->data = "[Error]";
		buf->size = strlen("[Error]");
	}
	return (buf->data);
}
Exemplo n.º 3
0
/*
 * __wt_bt_read --
 *	Read a cookie referenced block into a buffer.
 */
int
__wt_bt_read(WT_SESSION_IMPL *session,
    WT_ITEM *buf, const uint8_t *addr, size_t addr_size)
{
	WT_BM *bm;
	WT_BTREE *btree;
	WT_DECL_ITEM(tmp);
	WT_DECL_RET;
	const WT_PAGE_HEADER *dsk;
	size_t result_len;

	btree = S2BT(session);
	bm = btree->bm;

	/*
	 * If anticipating a compressed block, read into a scratch buffer and
	 * decompress into the caller's buffer.  Else, read directly into the
	 * caller's buffer.
	 */
	if (btree->compressor == NULL) {
		WT_RET(bm->read(bm, session, buf, addr, addr_size));
		dsk = buf->data;
	} else {
		WT_RET(__wt_scr_alloc(session, 0, &tmp));
		WT_ERR(bm->read(bm, session, tmp, addr, addr_size));
		dsk = tmp->data;
	}

	/*
	 * If the block is compressed, copy the skipped bytes of the original
	 * image into place, then decompress.
	 */
	if (F_ISSET(dsk, WT_PAGE_COMPRESSED)) {
		if (btree->compressor == NULL ||
		    btree->compressor->decompress == NULL)
			WT_ERR_MSG(session, WT_ERROR,
			    "read compressed block where no compression engine "
			    "configured");

		/*
		 * We're allocating the exact number of bytes we're expecting
		 * from decompression.
		 */
		WT_ERR(__wt_buf_initsize(session, buf, dsk->mem_size));

		/*
		 * Note the source length is NOT the number of compressed bytes,
		 * it's the length of the block we just read (minus the skipped
		 * bytes).  We don't store the number of compressed bytes: some
		 * compression engines need that length stored externally, they
		 * don't have markers in the stream to signal the end of the
		 * compressed bytes.  Those engines must store the compressed
		 * byte length somehow, see the snappy compression extension for
		 * an example.
		 */
		memcpy(buf->mem, tmp->data, WT_BLOCK_COMPRESS_SKIP);
		ret = btree->compressor->decompress(
		    btree->compressor, &session->iface,
		    (uint8_t *)tmp->data + WT_BLOCK_COMPRESS_SKIP,
		    tmp->size - WT_BLOCK_COMPRESS_SKIP,
		    (uint8_t *)buf->mem + WT_BLOCK_COMPRESS_SKIP,
		    dsk->mem_size - WT_BLOCK_COMPRESS_SKIP, &result_len);

		/*
		 * If checksums were turned off because we're depending on the
		 * decompression to fail on any corrupted data, we'll end up
		 * here after corruption happens.  If we're salvaging the file,
		 * it's OK, otherwise it's really, really bad.
		 */
		if (ret != 0 ||
		    result_len != dsk->mem_size - WT_BLOCK_COMPRESS_SKIP)
			WT_ERR(
			    F_ISSET(btree, WT_BTREE_VERIFY) ||
			    F_ISSET(session, WT_SESSION_SALVAGE_CORRUPT_OK) ?
			    WT_ERROR :
			    __wt_illegal_value(session, btree->dhandle->name));
	} else
		if (btree->compressor == NULL)
			buf->size = dsk->mem_size;
		else
			/*
			 * We guessed wrong: there was a compressor, but this
			 * block was not compressed, and now the page is in the
			 * wrong buffer and the buffer may be of the wrong size.
			 * This should be rare, but happens with small blocks
			 * that aren't worth compressing.
			 */
			WT_ERR(__wt_buf_set(
			    session, buf, tmp->data, dsk->mem_size));

	/* If the handle is a verify handle, verify the physical page. */
	if (F_ISSET(btree, WT_BTREE_VERIFY)) {
		if (tmp == NULL)
			WT_ERR(__wt_scr_alloc(session, 0, &tmp));
		WT_ERR(bm->addr_string(bm, session, tmp, addr, addr_size));
		WT_ERR(__wt_verify_dsk(session, (const char *)tmp->data, buf));
	}

	WT_STAT_FAST_CONN_INCR(session, cache_read);
	WT_STAT_FAST_DATA_INCR(session, cache_read);
	if (F_ISSET(dsk, WT_PAGE_COMPRESSED))
		WT_STAT_FAST_DATA_INCR(session, compress_read);
	WT_STAT_FAST_CONN_INCRV(session, cache_bytes_read, dsk->mem_size);
	WT_STAT_FAST_DATA_INCRV(session, cache_bytes_read, dsk->mem_size);

err:	__wt_scr_free(session, &tmp);
	return (ret);
}
Exemplo n.º 4
0
Arquivo: bt_io.c Projeto: qihsh/mongo
/*
 * __wt_bt_read --
 *	Read a cookie referenced block into a buffer.
 */
int
__wt_bt_read(WT_SESSION_IMPL *session,
    WT_ITEM *buf, const uint8_t *addr, size_t addr_size)
{
	WT_BM *bm;
	WT_BTREE *btree;
	WT_DECL_ITEM(etmp);
	WT_DECL_ITEM(tmp);
	WT_DECL_RET;
	WT_ENCRYPTOR *encryptor;
	WT_ITEM *ip;
	const WT_PAGE_HEADER *dsk;
	const char *fail_msg;
	size_t result_len;

	btree = S2BT(session);
	bm = btree->bm;
	fail_msg = NULL;			/* -Wuninitialized */

	/*
	 * If anticipating a compressed or encrypted block, read into a scratch
	 * buffer and decompress into the caller's buffer.  Else, read directly
	 * into the caller's buffer.
	 */
	if (btree->compressor == NULL && btree->kencryptor == NULL) {
		WT_RET(bm->read(bm, session, buf, addr, addr_size));
		dsk = buf->data;
		ip = NULL;
	} else {
		WT_RET(__wt_scr_alloc(session, 0, &tmp));
		WT_ERR(bm->read(bm, session, tmp, addr, addr_size));
		dsk = tmp->data;
		ip = tmp;
	}

	/*
	 * If the block is encrypted, copy the skipped bytes of the original
	 * image into place, then decrypt.
	 */
	if (F_ISSET(dsk, WT_PAGE_ENCRYPTED)) {
		if (btree->kencryptor == NULL ||
		    (encryptor = btree->kencryptor->encryptor) == NULL ||
		    encryptor->decrypt == NULL) {
			fail_msg =
			    "encrypted block in file for which no encryption "
			    "configured";
			goto corrupt;
		}

		WT_ERR(__wt_scr_alloc(session, 0, &etmp));
		if ((ret = __wt_decrypt(session,
		    encryptor, WT_BLOCK_ENCRYPT_SKIP, ip, etmp)) != 0) {
			fail_msg = "block decryption failed";
			goto corrupt;
		}

		ip = etmp;
		dsk = ip->data;
	} else if (btree->kencryptor != NULL) {
		fail_msg =
		    "unencrypted block in file for which encryption configured";
		goto corrupt;
	}

	if (F_ISSET(dsk, WT_PAGE_COMPRESSED)) {
		if (btree->compressor == NULL ||
		    btree->compressor->decompress == NULL) {
			fail_msg =
			    "compressed block in file for which no compression "
			    "configured";
			goto corrupt;
		}

		/*
		 * Size the buffer based on the in-memory bytes we're expecting
		 * from decompression.
		 */
		WT_ERR(__wt_buf_initsize(session, buf, dsk->mem_size));

		/*
		 * Note the source length is NOT the number of compressed bytes,
		 * it's the length of the block we just read (minus the skipped
		 * bytes).  We don't store the number of compressed bytes: some
		 * compression engines need that length stored externally, they
		 * don't have markers in the stream to signal the end of the
		 * compressed bytes.  Those engines must store the compressed
		 * byte length somehow, see the snappy compression extension for
		 * an example.
		 */
		memcpy(buf->mem, ip->data, WT_BLOCK_COMPRESS_SKIP);
		ret = btree->compressor->decompress(
		    btree->compressor, &session->iface,
		    (uint8_t *)ip->data + WT_BLOCK_COMPRESS_SKIP,
		    tmp->size - WT_BLOCK_COMPRESS_SKIP,
		    (uint8_t *)buf->mem + WT_BLOCK_COMPRESS_SKIP,
		    dsk->mem_size - WT_BLOCK_COMPRESS_SKIP, &result_len);

		/*
		 * If checksums were turned off because we're depending on the
		 * decompression to fail on any corrupted data, we'll end up
		 * here after corruption happens.  If we're salvaging the file,
		 * it's OK, otherwise it's really, really bad.
		 */
		if (ret != 0 ||
		    result_len != dsk->mem_size - WT_BLOCK_COMPRESS_SKIP) {
			fail_msg = "block decryption failed";
			goto corrupt;
		}
	} else
		/*
		 * If we uncompressed above, the page is in the correct buffer.
		 * If we get here the data may be in the wrong buffer and the
		 * buffer may be the wrong size.  If needed, get the page
		 * into the destination buffer.
		 */
		if (ip != NULL)
			WT_ERR(__wt_buf_set(
			    session, buf, ip->data, dsk->mem_size));

	/* If the handle is a verify handle, verify the physical page. */
	if (F_ISSET(btree, WT_BTREE_VERIFY)) {
		if (tmp == NULL)
			WT_ERR(__wt_scr_alloc(session, 0, &tmp));
		WT_ERR(bm->addr_string(bm, session, tmp, addr, addr_size));
		WT_ERR(__wt_verify_dsk(session, tmp->data, buf));
	}

	WT_STAT_FAST_CONN_INCR(session, cache_read);
	WT_STAT_FAST_DATA_INCR(session, cache_read);
	if (F_ISSET(dsk, WT_PAGE_COMPRESSED))
		WT_STAT_FAST_DATA_INCR(session, compress_read);
	WT_STAT_FAST_CONN_INCRV(session, cache_bytes_read, dsk->mem_size);
	WT_STAT_FAST_DATA_INCRV(session, cache_bytes_read, dsk->mem_size);

	if (0) {
corrupt:	if (ret == 0)
			ret = WT_ERROR;
		if (!F_ISSET(btree, WT_BTREE_VERIFY) &&
		    !F_ISSET(session, WT_SESSION_QUIET_CORRUPT_FILE)) {
			__wt_err(session, ret, "%s", fail_msg);
			ret = __wt_illegal_value(session, btree->dhandle->name);
		}
	}

err:	__wt_scr_free(session, &tmp);
	__wt_scr_free(session, &etmp);
	return (ret);
}