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nostrdb: move everything to src

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Signed-off-by: William Casarin <jb55@jb55.com>
This commit is contained in:
William Casarin
2023-12-23 09:30:08 -08:00
committed by Daniel D’Aquino
parent 1fb88a912a
commit 1ffbd80c67
82 changed files with 34 additions and 82 deletions
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100
nostrdb/src/lmdb_util.h Normal file
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// Define callback function type
typedef bool (*lmdb_callback_t)(const MDB_val*, const MDB_val*);
int lmdb_foreach(MDB_txn *txn, MDB_dbi dbi, MDB_val *start, MDB_val *start_dup, callback_t cb, bool reverse) {
int success = 0;
MDB_cursor *cursor;
// Open a cursor on the provided transaction and database
int rc = mdb_cursor_open(txn, dbi, &cursor);
if (rc != 0)
return 0;
MDB_val k = *start, v = *start_dup;
MDB_cursor_op op = reverse ? MDB_PREV : MDB_NEXT;
// If we're scanning in reverse...
if (reverse) {
// Try to position the cursor at the first key-value pair where
// both the key and the value are greater than or equal to our
// starting point.
rc = mdb_cursor_get(cursor, &k, &v, MDB_GET_BOTH_RANGE);
if (rc == 0) {
if (v.mv_size != start_dup->mv_size ||
memcmp(v.mv_data, start_dup->mv_data, v.mv_size) != 0) {
// If the value doesn't match our starting
// point, step back to the previous record.
if (mdb_cursor_get(cursor, &k, &v, MDB_PREV) != 0)
goto cleanup;
}
} else {
// If we couldn't find a record that matches both our
// starting key and value, try to find a record that
// matches just our starting key.
if (mdb_cursor_get(cursor, &k, &v, MDB_SET) == 0) {
// If we find a match, move to the last value
// for this key, since we're scanning in
// reverse.
if (mdb_cursor_get(cursor, &k, &v, MDB_LAST_DUP) != 0)
goto cleanup;
} else {
// If we can't find a record with our starting
// key, try to find the first record with a key
// greater than our starting key.
if (mdb_cursor_get(cursor, &k, &v, MDB_SET_RANGE) == 0) {
// If we find such a record, step back
// to the previous record.
if (mdb_cursor_get(cursor, &k, &v, MDB_PREV) != 0)
goto cleanup;
} else {
// If we can't even find a record with
// a key greater than our starting key,
// fall back to starting from the last
// record in the database.
if (mdb_cursor_get(cursor, &k, &v, MDB_LAST) != 0)
goto cleanup;
}
}
}
// If we're not scanning in reverse...
else {
// Try to position the cursor at the first key-value
// pair where both the key and the value are greater
// than or equal to our starting point.
if (mdb_cursor_get(cursor, &k, &v, MDB_SET) != 0) {
// If we couldn't find a record that matches
// both our starting key and value, try to find
// a record that matches just our starting key.
if (mdb_cursor_get(cursor, &k, &v, MDB_SET_RANGE) != 0)
goto cleanup;
// If we can't find a record with our starting
// key, try to find the first record with a key
// greater than our starting key.
if (mdb_cursor_get(cursor, &k, &v, MDB_FIRST_DUP) != 0)
goto cleanup;
}
}
}
// Whether we're scanning forward or backward, start the actual
// iteration, moving one step at a time in the appropriate direction
// and calling the provided callback for each record.
do {
if (!cb(&k, &v))
goto cleanup;
} while (mdb_cursor_get(cursor, &k, &v, op) == 0);
// If we make it through the entire iteration without the callback
// returning false, return true to signal success.
success = 1;
cleanup:
mdb_cursor_close(cursor);
return success;
}