diff options
Diffstat (limited to 'src/third_party/wiredtiger/src/support/modify.c')
| -rw-r--r-- | src/third_party/wiredtiger/src/support/modify.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/src/third_party/wiredtiger/src/support/modify.c b/src/third_party/wiredtiger/src/support/modify.c index 15f8a33772f..228cfff7fea 100644 --- a/src/third_party/wiredtiger/src/support/modify.c +++ b/src/third_party/wiredtiger/src/support/modify.c @@ -8,6 +8,57 @@ #include "wt_internal.h" +#define WT_MODIFY_FOREACH_BEGIN(mod, p, nentries, napplied) \ + do { \ + const size_t *__p = p; \ + const uint8_t *__data = (const uint8_t *)(__p + (size_t)(nentries)*3); \ + int __i; \ + for (__i = 0; __i < (nentries); ++__i) { \ + memcpy(&(mod).data.size, __p++, sizeof(size_t)); \ + memcpy(&(mod).offset, __p++, sizeof(size_t)); \ + memcpy(&(mod).size, __p++, sizeof(size_t)); \ + (mod).data.data = __data; \ + __data += (mod).data.size; \ + if (__i < (napplied)) \ + continue; + +#define WT_MODIFY_FOREACH_END \ + } \ + } \ + while (0) + +/* + * __wt_modify_idempotent -- + * Check if a modify operation is idempotent. + */ +bool +__wt_modify_idempotent(const void *modify) +{ + WT_MODIFY mod; + const size_t *p; + size_t tmp; + int nentries; + + /* Get the number of modify entries. */ + p = modify; + memcpy(&tmp, p++, sizeof(size_t)); + nentries = (int)tmp; + + WT_MODIFY_FOREACH_BEGIN (mod, p, nentries, 0) + { + /* + * If the number of bytes being replaced doesn't match the + * number of bytes being written, we're resizing and the + * operation isn't idempotent. + */ + if (mod.size != mod.data.size) + return (false); + } + WT_MODIFY_FOREACH_END; + + return (true); +} + /* * __wt_modify_pack -- * Pack a modify structure into a buffer. |