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#ifndef PURE_STORE_H
#define PURE_STORE_H
#include "flow.h"
#include "result.h"
#include <stdint.h>
#define PURE_OBJECT_LIMIT ((2u * 6u + 32u) * 32768u + 8192u)
/* A document (what a host carries whole, as an HTTP body) is at most
* PURE_OBJECT_LIMIT bytes. A value the runtime owns (an app's list or text
* state: a key starting with '.', or a draft without a key) may grow to
* PURE_STATE_LIMIT: a table of a million rows is one such value. */
#define PURE_STATE_LIMIT (UINT64_C(1) << 30)
typedef struct {
void *mapping;
size_t mapped_size, object_size;
PureSpan body;
int64_t revision;
} PureStoredView;
PureResult pure_store_init(const char *path);
PureResult pure_store_get(const char *path, const char *key, size_t available,
PureStoredView *out);
PureResult pure_store_get_range(const char *path, const char *key, size_t offset,
size_t length, size_t available, PureStoredView *out);
/* Inspect once: guards and mapping refer to the same immutable file version.
* minimum preserves bounds checks from eliminated intermediate views.
* whole selects the suffix starting at offset; otherwise length is exact. */
PureResult pure_store_select(const char *path, const char *key, size_t offset,
size_t length, bool whole, size_t minimum,
size_t available, PureStoredView *out);
void pure_store_release(PureStoredView *);
PureResult pure_store_put(const char *path, const char *key, int64_t expected,
PureSpan body, int64_t *revision);
/* Atomic byte replacement: retain [0,offset), insert bytes, retain suffix after
* remove bytes. Check the expected revision and bounds under the same writer
* lock. expected=0 permits creating an empty base (offset=remove=0).
* Retained bytes use bounded scratch space or a selected platform file copy;
* never assembles a whole new object in application memory. The immutable
* file is still rewritten. max_size is the final-body policy from the
* prepared app and is checked with the current size under the writer lock. */
PureResult pure_store_splice(const char *path, const char *key, int64_t expected,
size_t offset, size_t remove, PureSpan insert,
size_t max_size, int64_t *revision);
/* Visit each stored key once; the order is store-defined. Returning false
* from visit stops early. key is valid only during the call. Hosts that
* browse documents use this instead of reading a store's file layout. */
PureResult pure_store_keys(const char *path, bool (*visit)(void *, const char *key),
void *context);
/* Fault hooks exist only in the separately built unit-test binary. */
typedef enum {
PURE_AFTER_HEADER, PURE_BEFORE_FILE_SYNC, PURE_BEFORE_RENAME, PURE_BEFORE_DIR_SYNC,
PURE_COPY_RANGE_UNSUPPORTED_AFTER_PARTIAL
} PureStoreStage;
#ifdef PURE_STORE_TEST
int pure_store_test_fault(PureStoreStage stage);
#endif
#endif
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