starting zero alloc parsing

1 files changed, 51 insertions, 0 deletions

diff --git a/src/Server/Payload.zig b/src/Server/Payload.zig
new file mode 100644
index 0000000..b512a81
--- /dev/null
+++ b/src/Server/Payload.zig
@@ -0,0 +1,51 @@
+const std = @import("std");
+const Reader = std.Io.Reader;
+const Writer = std.Io.Writer;
+const Allocator = std.mem.Allocator;
+
+const Payload = @This();
+
+len: u32,
+short: [128]u8,
+long: ?[]u8,
+
+pub fn read(alloc: Allocator, in: *Reader, bytes: usize) !Payload {
+    var res: Payload = .{
+        .len = @intCast(bytes),
+        .short = undefined,
+        .long = null,
+    };
+
+    try in.readSliceAll(res.short[0..@min(bytes, res.short.len)]);
+    if (bytes > res.short.len) {
+        const long = try alloc.alloc(u8, bytes - res.short.len);
+        errdefer alloc.free(long);
+        try in.readSliceAll(long);
+        res.long = long;
+    }
+    return res;
+}
+
+pub fn write(self: Payload, out: *Writer) !void {
+    std.debug.assert(out.buffer.len >= self.short.len);
+    std.debug.assert(self.len <= self.short.len or self.long != null);
+    try out.writeAll(self.short[0..@min(self.len, self.short.len)]);
+    if (self.long) |l| {
+        try out.writeAll(l);
+    }
+}
+
+pub fn deinit(self: Payload, alloc: Allocator) void {
+    if (self.long) |l| {
+        alloc.free(l);
+    }
+}
+
+pub fn dupe(self: Payload, alloc: Allocator) !Payload {
+    var res = self;
+    if (self.long) |l| {
+        res.long = try alloc.dupe(u8, l);
+    }
+    errdefer if (res.long) |l| alloc.free(l);
+    return res;
+}