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Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/15086 Why: An application built on top of RocksDB could use cache population reads through explicit snapshots and needs to know when the returned value has already been superseded, without a second point read. Previous behavior: Get and MultiGet returned the snapshot-visible value and optional timestamp but could not report a newer point update or covering range deletion. New behavior: experimental C++, C, and Java metadata-read APIs report newer committed puts, deletes, merges, and covering range tombstones; ordinary primary-DB writes completed before the read are guaranteed to be reported, racing writes remain best-effort, and true has no false positives. Implementation: metadata reads widen lookup behind read-callback hooks while keeping metadata-only state off passive common object layouts; per-key state stays in KeyContext/GetContext, ordinary MultiGet row-cache replay semantics are preserved, BlobDB/TTL use shared output helpers, dead single-CF plumbing and an invalid cross-key stress assertion are removed, and the range-tombstone ordering invariant is documented without changing behavior. Safety and unsupported cases: tracking is opt-in and requires an explicit snapshot; persisted-tier reads, custom transactional visibility callbacks, secondary DBs, and unsupported subclasses return NotSupported, while read-only/compacted DBs return false because their in-process views are static. Tests and limitations: 1,265 Buck tests plus focused metadata, 100x coerced-context-switch row-cache, write-committed/write-prepared crash tests, builds, and lint passed. Current-parent release db_bench found no material passive regression: readrandom +0.65%, MultiGet batch 4 -1.40%, and batch 32 +0.48%. Reviewed By: pdillinger Differential Revision: D104182397 fbshipit-source-id: 36f7be1cd50fe2383689adaae31a6bb7d7e462dc