diff options
Diffstat (limited to 'db2/include/db_page.h')
| -rw-r--r-- | db2/include/db_page.h | 31 |
1 files changed, 23 insertions, 8 deletions
diff --git a/db2/include/db_page.h b/db2/include/db_page.h index 9e78682c57..cde7ff9f2e 100644 --- a/db2/include/db_page.h +++ b/db2/include/db_page.h @@ -4,7 +4,7 @@ * Copyright (c) 1996, 1997 * Sleepycat Software. All rights reserved. * - * @(#)db_page.h 10.10 (Sleepycat) 8/18/97 + * @(#)db_page.h 10.11 (Sleepycat) 9/3/97 */ #ifndef _DB_PAGE_H_ @@ -400,6 +400,24 @@ typedef struct _hoffdup { #define B_OVERFLOW 3 /* Overflow key/data item. */ /* + * We have to store a deleted entry flag in the page. The reason is complex, + * but the simple version is that we can't delete on-page items referenced by + * a cursor -- the return order of subsequent insertions might be wrong. The + * delete flag is an overload of the top bit of the type byte. + */ +#define B_DELETE (0x80) +#define B_DCLR(t) (t) &= ~B_DELETE +#define B_DSET(t) (t) |= B_DELETE +#define B_DISSET(t) ((t) & B_DELETE) + +#define B_TYPE(t) ((t) & ~B_DELETE) +#define B_TSET(t, type, deleted) { \ + (t) = (type); \ + if (deleted) \ + B_DSET(t); \ +} + +/* * The first type is B_KEYDATA, represented by the BKEYDATA structure: * * +-----------------------------------+ @@ -408,8 +426,7 @@ typedef struct _hoffdup { */ typedef struct _bkeydata { db_indx_t len; /* 00-01: Key/data item length. */ - u_int deleted :1; /* 02: Page type and delete flag. */ - u_int type :7; + u_int8_t type; /* 02: Page type AND DELETE FLAG. */ u_int8_t data[1]; /* Variable length key/data item. */ } BKEYDATA; @@ -438,8 +455,7 @@ typedef struct _bkeydata { */ typedef struct _boverflow { db_indx_t unused1; /* 00-01: Padding, unused. */ - u_int deleted :1; /* 02: Page type and delete flag. */ - u_int type :7; + u_int8_t type; /* 02: Page type AND DELETE FLAG. */ u_int8_t unused2; /* 03: Padding, unused. */ db_pgno_t pgno; /* 04-07: Next page number. */ u_int32_t tlen; /* 08-11: Total length of item. */ @@ -479,9 +495,8 @@ typedef struct _boverflow { * +-----------------------------------+ */ typedef struct _binternal { - db_indx_t len; /* 00-01: Key/data item length. */ - u_int deleted :1; /* 02: Page type and delete flag. */ - u_int type :7; + db_indx_t len; /* 00-01: Key/data item length. */ + u_int8_t type; /* 02: Page type AND DELETE FLAG. */ u_int8_t unused; /* 03: Padding, unused. */ db_pgno_t pgno; /* 04-07: Page number of referenced page. */ db_recno_t nrecs; /* 08-11: Subtree record count. */ |