Added template for lock file, it is 100% a work in progress.

src/tablestream/templates/lock.ksy

@@ -0,0 +1,89 @@
+meta:
+  id: lock
+  endian: be
+  file-extension: lock
+  imports:
+    - dtype
+
+doc: |
+    There are some issues with this, I need to ffigure them out but it is at least partly correct...
+
+seq:
+    - id: fcntl
+      type: u1
+      doc: |
+        Acquire/release of lock can be shared (read) or exclusive (write)
+    - id: proc
+      type: u1
+      doc: |
+        Tells other processes that table is open. Creates a shared lock.
+    - id: lock_type
+      type: u1
+      doc: |
+        Permanent or shared lock.
+    - id: special
+      type: u1
+      repeat: expr
+      repeat-expr: 3
+      doc: |
+        Special internal lock usage.
+    - id: lock_info
+      type: u2
+      repeat: expr
+      repeat-expr: 127
+      doc: |
+        There is structure in here but I'm not filling it in yet. This should
+        describe the list of processes trying to access the data.
+    - id: stream_length
+      type: u4
+    - id: apsio_header
+      type: header
+    - id: number_rows
+      type:
+        switch-on: apsio_header.version
+        cases:
+          0: u4
+          1: u4
+          2: u8
+    - id: number_columns
+      type: u4
+    - id: modify_column
+      type: u4
+    - id: change_counter
+      type: u4
+      doc: |
+        Counter incremented if the table.dat has changed.
+    - id: block
+      type: data_block
+
+
+types:
+  header:
+    seq:
+      - id: magic
+        contents: [ 0xbe, 0xbe, 0xbe, 0xbe ]
+        doc: |
+          casa magic unsigned int 3200171710  190 190 190 190
+      - id: size
+        type: u4
+      - id: type
+        type: dtype::string
+      - id: version
+        type: u1
+
+  data_block:
+    seq:
+      - id: number_rows
+        type: u4
+      - id: filler
+        type: u2
+      - id: idk
+        type: u1
+      - id: name
+        type: dtype::string
+      - id: size
+        type: u4
+        repeat: expr
+        repeat-expr: 25
+        doc: |
+          I just did this to figure out how much data there was.