tiny.sql.RowValueStorage

1pub const ValueStorage = struct {2    phase: alloc_phase.capacity.Phase,3    capacity: ValueCapacity,4    bytes: []u8,56    pub const Limits: type = ValueLimits;7    pub const Capacity: type = ValueCapacity;8    pub const Exhaustion = error{ValueCapacityExceeded};9    pub const InitError: type = Allocator.Error;1011    pub const claim: alloc_phase.capacity.Declaration = .{12        .source = .{13            .id = "sql.table_value_storage",14            .kind = .phase_static,15            .limit_source = .caller,16            .storage = .{17                .covered = &.{18                    .{19                        .id = "one_reusable_encoded_row_value_region",20                        .lifetime = .steady,21                        .detail = "one reusable encoded row value region",22                    },23                },24                .excluded = &.{25                    "tree traversal, database/WAL bytes, file handles, and operating-system page cache",26                    "file read cache, pager history, search hit storage, and decoded result fields",27                    "caller-owned keys and trace instrumentation",28                },29            },30            .capacity = .{31                .inputs = &.{32                    alloc_phase.capacity.bindInput(Limits, "max_value_bytes", "max_value_bytes"),33                },34                .type_selectors = &.{},35                .nodes = &.{36                    .{ .input = 0 },37                },38                .assertions = &.{.{39                    .scope = .closure_total,40                    .measure = .retained,41                    .relation = .exact,42                    .expression = 0,43                }},44            },45            .overload = .{46                .kind = .reject_before_mutation,47                .detail = "oversize values return ValueCapacityExceeded before reusable bytes mutate",48            },49            .risks = .{50                .transitive = .{51                    .status = .open,52                    .detail = "tree reads use separate file, pager, cache, and trace owners",53                },54                .foreign = .{55                    .status = .open,56                    .detail = "base-page reads may enter the host filesystem and OS cache",57                },58            },59            .obligations = &.{60                .{ .key = "sql_table_value_capacity", .role = .capacity_model },61                .{ .key = "sql_table_value_oom_retry", .role = .custom },62                .{ .key = "sql_table_value_sealed", .role = .overload },63                .{ .key = "sql_table_value_semantics", .role = .custom },64            },65        },66        .bindings = .{67            .owner = @This(),68            .seal = .{69                .family = alloc_phase.capacity.selector(@This().activate),70                .premise = .{71                    .class = .checked_semantic_fact,72                    .authority = .checker,73                },74            },75            .teardown = .{76                .family = alloc_phase.capacity.selector(@This().deinit),77                .premise = .{78                    .class = .checked_semantic_fact,79                    .authority = .checker,80                },81            },82        },83    };8485    pub fn init(allocator: Allocator, limits: ValueLimits) InitError!ValueStorage {86        const capacity = ValueCapacity.derive(limits);87        const bytes = if (capacity.storage_bytes == 0)88            @as([]u8, &.{})89        else90            try allocator.alloc(u8, capacity.storage_bytes);91        return .{92            .phase = .initialization,93            .capacity = capacity,94            .bytes = bytes,95        };96    }9798    pub fn activate(self: *ValueStorage) void {99        std.debug.assert(self.phase == .initialization);100        std.debug.assert(self.bytes.len == self.capacity.storage_bytes);101        self.phase = .steady;102    }103104    pub fn get(105        self: *ValueStorage,106        table: *const Table,107        rowid: i64,108    ) (Error || Exhaustion)!?[]const u8 {109        std.debug.assert(self.phase == .steady);110        const value = table.getInto(rowid, self.bytes) catch |err| switch (err) {111            error.OutputTooSmall => return error.ValueCapacityExceeded,112            else => return err,113        };114        return value;115    }116117    pub fn deinit(self: *ValueStorage, allocator: Allocator) void {118        std.debug.assert(self.phase != .teardown);119        std.debug.assert(self.bytes.len == self.capacity.storage_bytes);120        self.phase = .teardown;121        if (self.bytes.len != 0) allocator.free(self.bytes);122        self.bytes = &.{};123    }124};

1pub const RowValueStorage = table.ValueStorage;