tiny.choir.serialization.binary

1pub const Error = error{2    Truncated,3    InvalidValue,4    InvalidTag,5    LimitExceeded,6};

1pub const Limits = struct {2    serialized_bytes: usize,3    string_bytes: usize,4    blob_bytes: usize,5    collection_entries: usize,6    total_entries: usize,7};

1pub fn Reader(comptime limits: binary.Limits) type {2    return struct {3        bytes: []const u8,4        offset: usize = 0,5        total_entries: usize = 0,67        const Self = @This();89        pub fn init(bytes: []const u8) binary.Error!Self {10            if (bytes.len > limits.serialized_bytes) return error.LimitExceeded;11            return .{ .bytes = bytes };12        }1314        pub fn atEnd(self: Self) bool {15            return self.offset == self.bytes.len;16        }1718        pub fn readRaw(self: *Self, length: usize) binary.Error![]const u8 {19            if (length > self.bytes.len - self.offset) return error.Truncated;20            const value = self.bytes[self.offset..][0..length];21            self.offset += length;22            return value;23        }2425        pub fn readInt(self: *Self, comptime T: type) binary.Error!T {26            const value = try self.readRaw(@sizeOf(T));27            return std.mem.readInt(T, value[0..@sizeOf(T)], .little);28        }2930        pub fn readBool(self: *Self) binary.Error!bool {31            return switch (try self.readInt(u8)) {32                0 => false,33                1 => true,34                else => error.InvalidValue,35            };36        }3738        pub fn readTag(self: *Self, comptime T: type) binary.Error!T {39            return try binary.decodeTag(T, try self.readInt(u8));40        }4142        pub fn readCount(self: *Self) binary.Error!usize {43            const count: usize = @intCast(try self.readInt(u32));44            if (count > limits.collection_entries) return error.LimitExceeded;45            if (count > self.bytes.len - self.offset) return error.Truncated;46            self.total_entries = std.math.add(usize, self.total_entries, count) catch return error.LimitExceeded;47            if (self.total_entries > limits.total_entries) return error.LimitExceeded;48            return count;49        }5051        pub fn readString(self: *Self) binary.Error![]const u8 {52            return try self.readLengthPrefixed(limits.string_bytes);53        }5455        pub fn readBlob(self: *Self) binary.Error![]const u8 {56            return try self.readLengthPrefixed(limits.blob_bytes);57        }5859        pub fn readOptionalString(self: *Self) binary.Error!?[]const u8 {60            if (!try self.readBool()) return null;61            return try self.readString();62        }6364        pub fn readOptionalU16(self: *Self) binary.Error!?u16 {65            if (!try self.readBool()) return null;66            return try self.readInt(u16);67        }6869        fn readLengthPrefixed(self: *Self, maximum: usize) binary.Error![]const u8 {70            const length: usize = @intCast(try self.readInt(u32));71            if (length > maximum) return error.LimitExceeded;72            return try self.readRaw(length);73        }74    };75}

1pub fn decodeTag(comptime T: type, value: u8) error{InvalidTag}!T {2    return std.enums.fromInt(T, value) orelse error.InvalidTag;3}

1pub fn encodeTag(value: anytype) error{LimitExceeded}!u8 {2    return std.math.cast(u8, @backingInt(value)) orelse error.LimitExceeded;3}

1/// Has no allocator capability. Its finished bytes borrow the caller's buffer.2pub fn FixedWriter(comptime limits: binary.Limits) type {3    return BufferWriter(limits, .borrowed);4}

1pub fn Writer(comptime limits: binary.Limits) type {2    return BufferWriter(limits, .allocated);3}

1const model = @import("model.zig");2const tag = @import("tag.zig");34pub const Limits = model.Limits;5pub const Error = model.Error;6pub const WriteError = model.WriteError;7pub const Reader = @import("reader.zig").Reader;8pub const Writer = @import("writer.zig").Writer;9pub const FixedWriter = @import("writer.zig").FixedWriter;10pub const encodeTag = tag.encodeTag;11pub const decodeTag = tag.decodeTag;

1pub const binary = @import("binary/root.zig");