feat: blocktxn

src/network/protocol/messages/blocktxn.zig

@@ -0,0 +1,128 @@
+const std = @import("std");
+const protocol = @import("../lib.zig");
+
+const Sha256 = std.crypto.hash.sha2.Sha256;
+const BlockHeader = @import("../../../types/block_header.zig");
+const CompactSizeUint = @import("bitcoin-primitives").types.CompatSizeUint;
+const genericChecksum = @import("lib.zig").genericChecksum;
+/// BlockTxnMessage represents the "BlockTxn" message
+///
+/// https://developer.bitcoin.org/reference/p2p_networking.html#blocktxn
+pub const BlockTxnMessage = struct {
+    block_hash: [32]u8,
+    indexes: []CompactSizeUint,
+
+    const Self = @This();
+
+    pub fn name() *const [12]u8 {
+        return protocol.CommandNames.BLOCKTXN ++ [_]u8{0} ** 4;
+    }
+
+    /// Returns the message checksum
+    pub fn checksum(self: *const Self) [4]u8 {
+        return genericChecksum(self);
+    }
+
+    /// Free the allocated memory
+    pub fn deinit(self: *const Self, allocator: std.mem.Allocator) void {
+        allocator.free(self.indexes);
+    }
+
+    /// Serialize the message as bytes and write them to the Writer.
+    pub fn serializeToWriter(self: *const Self, w: anytype) !void {
+        comptime {
+            if (!std.meta.hasFn(@TypeOf(w), "writeInt")) @compileError("Expects r to have fn 'writeInt'.");
+            if (!std.meta.hasFn(@TypeOf(w), "writeAll")) @compileError("Expects r to have fn 'writeAll'.");
+        }
+        try w.writeAll(&self.block_hash);
+        const indexes_count = CompactSizeUint.new(self.indexes.len);
+        try indexes_count.encodeToWriter(w);
+        for (self.indexes) |*index| {
+            try index.encodeToWriter(w);
+        }
+    }
+    /// Serialize a message as bytes and write them to the buffer.
+    ///
+    /// buffer.len must be >= than self.hintSerializedLen()
+    pub fn serializeToSlice(self: *const Self, buffer: []u8) !void {
+        var fbs = std.io.fixedBufferStream(buffer);
+        try self.serializeToWriter(fbs.writer());
+    }
+
+    /// Serialize a message as bytes and return them.
+    pub fn serialize(self: *const Self, allocator: std.mem.Allocator) ![]u8 {
+        const serialized_len = self.hintSerializedLen();
+        const ret = try allocator.alloc(u8, serialized_len);
+        errdefer allocator.free(ret);
+
+        try self.serializeToSlice(ret);
+
+        return ret;
+    }
+
+    /// Returns the hint of the serialized length of the message.
+    pub fn hintSerializedLen(self: *const Self) usize {
+        // 32 bytes for the block header
+        const fixed_length = 32;
+
+        const indexes_count_length: usize = CompactSizeUint.new(self.indexes.len).hint_encoded_len();
+
+        var compact_indexes_length: usize = 0;
+        for (self.indexes) |index| {
+            compact_indexes_length += index.hint_encoded_len();
+        }
+
+        const variable_length = indexes_count_length + compact_indexes_length;
+
+        return fixed_length + variable_length;
+    }
+
+    pub fn deserializeReader(allocator: std.mem.Allocator, r: anytype) !Self {
+        var blocktxn_message: Self = undefined;
+        try r.readNoEof(&blocktxn_message.block_hash);
+
+        const indexes_count = try CompactSizeUint.decodeReader(r);
+        blocktxn_message.indexes = try allocator.alloc(CompactSizeUint, indexes_count.value());
+        errdefer allocator.free(blocktxn_message.indexes);
+
+        for (blocktxn_message.indexes) |*index| {
+            index.* = try CompactSizeUint.decodeReader(r);
+        }
+
+        return blocktxn_message;
+    }
+
+    /// Deserialize bytes into a `BlockTxnMessage`
+    pub fn deserializeSlice(allocator: std.mem.Allocator, bytes: []const u8) !Self {
+        var fbs = std.io.fixedBufferStream(bytes);
+        return try Self.deserializeReader(allocator, fbs.reader());
+    }
+
+    pub fn new(block_hash: [32]u8, indexes: []CompactSizeUint) Self {
+        return .{
+            .block_hash = block_hash,
+            .indexes = indexes,
+        };
+    }
+};
+
+test "BlockTxnMessage serialization and deserialization" {
+    const test_allocator = std.testing.allocator;
+
+    const block_hash: [32]u8 = [_]u8{0} ** 32;
+    const indexes = try test_allocator.alloc(CompactSizeUint, 1);
+    indexes[0] = CompactSizeUint.new(123);
+    const msg = BlockTxnMessage.new(block_hash, indexes);
+
+    defer msg.deinit(test_allocator);
+
+    const serialized = try msg.serialize(test_allocator);
+    defer test_allocator.free(serialized);
+
+    const deserialized = try BlockTxnMessage.deserializeSlice(test_allocator, serialized);
+    defer deserialized.deinit(test_allocator);
+
+    try std.testing.expectEqual(msg.block_hash, deserialized.block_hash);
+    try std.testing.expectEqual(msg.indexes[0].value(), msg.indexes[0].value());
+    try std.testing.expectEqual(msg.hintSerializedLen(), 32 + 1 + 1);
+}

src/network/protocol/messages/lib.zig

@@ -17,6 +17,7 @@ const Sha256 = std.crypto.hash.sha2.Sha256;
 pub const NotFoundMessage = @import("notfound.zig").NotFoundMessage;
 pub const SendHeadersMessage = @import("sendheaders.zig").SendHeadersMessage;
 pub const FilterLoadMessage = @import("filterload.zig").FilterLoadMessage;
+pub const BlockTxnMessage = @import("blocktxn.zig").BlockTxnMessage;
 
 pub const InventoryVector = struct {
     type: u32,
@@ -65,6 +66,7 @@ pub const MessageTypes = enum {
     notfound,
     sendheaders,
     filterload,
+    blocktxn,
 };
 
 pub const Message = union(MessageTypes) {
@@ -84,6 +86,7 @@ pub const Message = union(MessageTypes) {
     notfound: NotFoundMessage,
     sendheaders: SendHeadersMessage,
     filterload: FilterLoadMessage,
+    blocktxn: BlockTxnMessage,
 
     pub fn name(self: Message) *const [12]u8 {
         return switch (self) {
@@ -103,6 +106,7 @@ pub const Message = union(MessageTypes) {
             .notfound => |m| @TypeOf(m).name(),
             .sendheaders => |m| @TypeOf(m).name(),
             .filterload => |m| @TypeOf(m).name(),
+            .blocktxn => |m| @TypeOf(m).name(),
         };
     }
 
@@ -124,6 +128,7 @@ pub const Message = union(MessageTypes) {
             .notfound => {},
             .sendheaders => {},
             .filterload => {},
+            .blocktxn => |*m| m.deinit(allocator),
         }
     }
 
@@ -145,6 +150,7 @@ pub const Message = union(MessageTypes) {
             .notfound => |*m| m.checksum(),
             .sendheaders => |*m| m.checksum(),
             .filterload => |*m| m.checksum(),
+            .blocktxn => |*m| m.checksum(),
         };
     }
 
@@ -166,6 +172,7 @@ pub const Message = union(MessageTypes) {
             .notfound => |m| m.hintSerializedLen(),
             .sendheaders => |m| m.hintSerializedLen(),
             .filterload => |*m| m.hintSerializedLen(),
+            .blocktxn => |*m| m.hintSerializedLen(),
         };
     }
 };

src/network/protocol/messages/merkleblock.zig

@@ -33,6 +33,10 @@ pub const MerkleBlockMessage = struct {
 
     /// Serialize the message as bytes and write them to the Writer.
     pub fn serializeToWriter(self: *const Self, w: anytype) !void {
+        comptime {
+            if (!std.meta.hasFn(@TypeOf(w), "writeInt")) @compileError("Expects w to have fn 'writeInt'.");
+            if (!std.meta.hasFn(@TypeOf(w), "writeAll")) @compileError("Expects w to have fn 'writeAll'.");
+        }
         try self.block_header.serializeToWriter(w);
         try w.writeInt(u32, self.transaction_count, .little);
         const hash_count = CompactSizeUint.new(self.hashes.len);
@@ -78,6 +82,11 @@ pub const MerkleBlockMessage = struct {
     }
 
     pub fn deserializeReader(allocator: std.mem.Allocator, r: anytype) !Self {
+        comptime {
+            if (!std.meta.hasFn(@TypeOf(r), "readInt")) @compileError("Expects r to have fn 'readInt'.");
+            if (!std.meta.hasFn(@TypeOf(r), "readNoEof")) @compileError("Expects r to have fn 'readNoEof'.");
+        }
+
         var merkle_block_message: Self = undefined;
         merkle_block_message.block_header = try BlockHeader.deserializeReader(r);
         merkle_block_message.transaction_count = try r.readInt(u32, .little);

src/network/wire/lib.zig

@@ -19,6 +19,8 @@ pub const Error = error{
 };
 
 const BlockHeader = @import("../../types/block_header.zig");
+const CompactSizeUint = @import("bitcoin-primitives").types.CompatSizeUint;
+
 /// Return the checksum of a slice
 ///
 /// Use it on serialized messages to compute the header's value
@@ -141,6 +143,8 @@ pub fn receiveMessage(
         protocol.messages.Message{ .sendheaders = try protocol.messages.SendHeadersMessage.deserializeReader(allocator, r) }
     else if (std.mem.eql(u8, &command, protocol.messages.FilterLoadMessage.name()))
         protocol.messages.Message{ .filterload = try protocol.messages.FilterLoadMessage.deserializeReader(allocator, r) }
+    else if (std.mem.eql(u8, &command, protocol.messages.BlockTxnMessage.name()))
+        protocol.messages.Message{ .blocktxn = try protocol.messages.BlockTxnMessage.deserializeReader(allocator, r) }
     else {
         try r.skipBytes(payload_len, .{}); // Purge the wire
         return error.UnknownMessage;
@@ -431,6 +435,39 @@ test "ok_send_sendheaders_message" {
     }
 }
 
+test "ok_send_blocktxn_message" {
+    const Config = @import("../../config/config.zig").Config;
+    const ArrayList = std.ArrayList;
+    const test_allocator = std.testing.allocator;
+    const BlockTxnMessage = protocol.messages.BlockTxnMessage;
+
+    var list: std.ArrayListAligned(u8, null) = ArrayList(u8).init(test_allocator);
+    defer list.deinit();
+
+    const block_hash = [_]u8{0} ** 32;
+    const indexes = try test_allocator.alloc(CompactSizeUint, 1);
+    indexes[0] = CompactSizeUint.new(1000);
+    defer test_allocator.free(indexes);
+    const message = BlockTxnMessage.new(block_hash, indexes);
+
+    var received_message = try write_and_read_message(
+        test_allocator,
+        &list,
+        Config.BitcoinNetworkId.MAINNET,
+        Config.PROTOCOL_VERSION,
+        message,
+    ) orelse unreachable;
+    defer received_message.deinit(test_allocator);
+
+    switch (received_message) {
+        .blocktxn => {
+            try std.testing.expectEqual(message.block_hash, received_message.blocktxn.block_hash);
+            try std.testing.expectEqual(indexes[0].value(), received_message.blocktxn.indexes[0].value());
+        },
+        else => unreachable,
+    }
+}
+
 test "ko_receive_invalid_payload_length" {
     const Config = @import("../../config/config.zig").Config;
     const ArrayList = std.ArrayList;