4 files changed, 45 insertions(+), 1 deletions(-)

M src/alys.cr
A src/alys/VERSION
M tools/alys_converter.cr
A tools/update_version.sh

@@ 116,6 116,13 @@ module Alys::Internal
     Free
   end
 
+  PROTOCOL_VERSION = {{ read_file("#{__DIR__}/alys/VERSION").strip.id + "u32" }}
+
+  @[Packed]
+  record Header,
+    name : UInt8[4],
+    version : UInt32
+
   @[Packed]
   record Frame,
     ip : UInt64,


@@ 194,7 201,15 @@ module Alys::Internal
 
     Exception::CallStack.load_debug_info
 
-    @@fd = EventlessFd.open file
+    fd = EventlessFd.open file
+
+    name = StaticArray['A', 'L', 'Y', 'S'].map { |c| c.bytes[0] }
+    header = Header.new name: name, version: PROTOCOL_VERSION
+    fd.write_value header
+
+    # Don't save it until down here, since the previous lines would have started
+    # allocations that would be written to this fd.
+    @@fd = fd
   end
 
   @@in_write = false

@@ 0,0 1,1 @@
+2022090801

@@ 30,12 30,20 @@ module ReadStructFromIO
   end
 end
 
+PROTOCOL_VERSION = Alys::Internal::PROTOCOL_VERSION
+
 alias EventKind = Alys::Internal::EventKind
+alias RawHeader = Alys::Internal::Header
 alias RawEvent = Alys::Internal::Event
 alias RawAllocEventExtra = Alys::Internal::AllocEventExtra
 alias RawReallocEventExtra = Alys::Internal::ReallocEventExtra
 alias RawFrame = Alys::Internal::Frame
 
+@[Packed]
+struct RawHeader
+  include ReadStructFromIO
+end
+
 struct RawEvent
   include ReadStructFromIO
 end


@@ 179,6 187,14 @@ class EventReader
 
     start_time = nil
 
+    header = RawHeader.from_io @source
+    puts header.name
+    raise "Bad file format" if String.new(header.name.to_slice) != "ALYS"
+
+    if header.version != PROTOCOL_VERSION
+      raise "Incompatible protocol version #{header.version} (supported: #{PROTOCOL_VERSION})"
+    end
+
     loop do
       begin
         raw_event = RawEvent.from_io @source

@@ 0,0 1,12 @@
+#!/bin/bash
+
+cd "$(dirname "$0")/.."
+
+version_file=src/alys/VERSION
+base_version=$(date -u +%F | tr -d '-')
+[[ -f "$version_file" ]] && current_version=$(< "$version_file")
+if [[ "$current_version" == "$base_version"* ]]; then
+  echo "$(($current_version + 1))" > "$version_file"
+else
+  echo "${base_version}01" > "$version_file"
+fi