tiny.sql.Store

1pub const Store = struct {2    allocator: Allocator,3    versions: std.ArrayList(Version) = .empty,4    generation: u64 = 0,56    pub fn init(allocator: Allocator) Store {7        return .{ .allocator = allocator };8    }910    pub fn deinit(self: *Store) void {11        for (self.versions.items) |*version| {12            freeOwned(self.allocator, version.key);13            if (!version.deleted) freeOwned(self.allocator, version.value);14        }15        self.versions.deinit(self.allocator);16        self.* = .{ .allocator = self.allocator };17    }1819    pub fn currentGeneration(self: *const Store) u64 {20        return self.generation;21    }2223    pub fn beginRead(self: *const Store) Snapshot {24        return .{ .store = self, .generation = self.generation };25    }2627    pub fn beginWrite(self: *Store) Write {28        return .{ .store = self, .snapshot_generation = self.generation };29    }3031    pub fn get(self: *const Store, key: []const u8) ?[]const u8 {32        const phase = trace.scope("store.get");33        defer phase.end();34        return valueFromIndex(self, latestVisibleIndex(self, key, self.generation));35    }3637    pub fn getAt(self: *const Store, key: []const u8, generation: u64) ?[]const u8 {38        return valueFromIndex(self, latestVisibleIndex(self, key, generation));39    }4041    pub fn range(self: *const Store, start: ?[]const u8, end: ?[]const u8) Error!Range {42        return rangeAt(self, start, end, self.generation);43    }4445    pub fn rangeAt(self: *const Store, start: ?[]const u8, end: ?[]const u8, generation: u64) Error!Range {46        if (start) |lower| {47            if (end) |upper| {48                if (simd.order(Bytes, lower, upper) == .gt) return error.InvalidRange;49            }50        }51        return .{52            .store = self,53            .start = start,54            .end = end,55            .generation = generation,56            .index = if (start) |lower| lowerBoundKey(self.versions.items, lower) else 0,57        };58    }5960    pub fn compact(self: *Store, oldest_visible_generation: u64) void {61        const phase = trace.scope("store.compact");62        defer phase.end();6364        var read_index: usize = 0;65        var write_index: usize = 0;66        while (read_index < self.versions.items.len) {67            const key = self.versions.items[read_index].key;68            var group_end = read_index;69            var has_oldest_version = false;70            while (group_end < self.versions.items.len and eqlKey(self.versions.items[group_end].key, key)) : (group_end += 1) {71                const version = self.versions.items[group_end];72                if (version.generation == oldest_visible_generation) has_oldest_version = true;73            }7475            var keep_floor: ?usize = null;76            var scan = read_index;77            while (scan < group_end) : (scan += 1) {78                const version = self.versions.items[scan];79                if (version.generation < oldest_visible_generation) {80                    if (keep_floor == null or self.versions.items[keep_floor.?].generation < version.generation) {81                        keep_floor = scan;82                    }83                }84            }8586            scan = read_index;87            while (scan < group_end) : (scan += 1) {88                const keep =89                    (!has_oldest_version and keep_floor != null and scan == keep_floor.?) or90                    self.versions.items[scan].generation >= oldest_visible_generation;91                if (keep) {92                    self.versions.items[write_index] = self.versions.items[scan];93                    write_index += 1;94                } else {95                    freeOwned(self.allocator, self.versions.items[scan].key);96                    if (!self.versions.items[scan].deleted) freeOwned(self.allocator, self.versions.items[scan].value);97                }98            }99100            read_index = group_end;101        }102        self.versions.shrinkRetainingCapacity(write_index);103    }104};

1pub const Store = store.Store;