From fb1b75490bbfc3cf10f13388e15231cb30314849 Mon Sep 17 00:00:00 2001
From: Magnus Ahltorp <map@kth.se>
Date: Wed, 10 Feb 2016 11:11:16 +0100
Subject: Rough implementation of new permdb format. Added regression tests and
 benchmarks. Chunks not implemented yet.

---
 test/listpermdb.erl | 133 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 133 insertions(+)
 create mode 100755 test/listpermdb.erl

(limited to 'test/listpermdb.erl')

diff --git a/test/listpermdb.erl b/test/listpermdb.erl
new file mode 100755
index 0000000..04acbfa
--- /dev/null
+++ b/test/listpermdb.erl
@@ -0,0 +1,133 @@
+#!/usr/bin/env escript
+%% -*- erlang -*-
+%%! -pa ebin -pa ../lager/ebin -pa ../lager/deps/goldrush/ebin
+
+-mode(compile).
+
+-include_lib("kernel/include/file.hrl").
+
+-define(DATA_COMMIT_START_COOKIE, 16#75c2e4b3d5f643a1).
+-define(DATA_COMMIT_END_COOKIE, 16#2b05eed61b5af550).
+-define(INDEX_COMMIT_END_COOKIE, 16#2fb1778c74a402e4).
+-define(DATA_FILE_COOKIE, 16#d53551ba539a4252).
+-define(INDEX_FILE_COOKIE, 16#b7e16b02ba8a6d1b).
+-define(DATA_ENTRY_COOKIE, 16#e7c1cdc2ba3dc77c).
+-define(INDEX_NODE_COOKIE, 16#2e0f555ad73210d1).
+
+openfile(Filename) ->
+    {ok, File} = file:open(Filename, [read, write, binary, raw]),
+    File.
+
+%% getroot(File) ->
+%%     {ok, RootNodeBinary} = file:read(File, ?NODESIZE),
+%%             Nodemagic = ?NODEMAGIC,
+%%             <<Nodemagic:2/binary, Node/binary>> = RootNodeBinary,
+%%             ets:insert(State#state.cachename, {root, Node}),
+%%             Node;
+%%         [{root, Node}] ->
+%%             Node
+%%     end.
+
+printfile(<<?INDEX_FILE_COOKIE:64/native, Rest/binary>>) ->
+    io:format("index file header~n", []),
+    printcommit(Rest, index, 8);
+printfile(<<?DATA_FILE_COOKIE:64, Blocksize:32, Q:32, Keylength:32, Rest/binary>>) ->
+    io:format("data file header: blocksize ~p q ~p keylength ~p~n", [Blocksize, Q, Keylength]),
+    printcommit(Rest, data, 8+4*3);
+printfile(<<Unknown:16/binary, _Rest/binary>>) ->
+    io:format("unknown byte: ~p at file start~n", [Unknown]),
+    error.
+
+printnode(<<>>) ->
+    ok;
+printnode(<<Child:64/native, Rest/binary>>) ->
+    case <<Child:64/big>> of
+        <<0:1, Offset:63>> ->
+            io:format("  child ~p~n", [Offset]);
+        <<1:1, Offset:63>> ->
+            io:format("  offset ~p~n", [Offset])
+    end,
+    printnode(Rest).
+
+printcommit(Data, FileType, FileOffset) ->
+    OneCommit = case FileType of
+                    index ->
+                        printindex(Data, FileOffset);
+                    data ->
+                        printdata(Data, FileOffset)
+                end,
+    case OneCommit of
+        {{CommitLength, CommitChecksum, Rest}, FileOffset2, FileOffset3} ->
+            io:format("------- commit ~p bytes at ~p-~p -------~n", [CommitLength, FileOffset, FileOffset3]),
+            CalculatedChecksum = crypto:hash(sha256, binary:part(Data, 0, CommitLength)),
+            if
+                CommitChecksum /= CalculatedChecksum ->
+                    io:format("incorrect checksum~n", []),
+                    io:format("commit: length ~p checksum ~p~n", [CommitLength, CommitChecksum]),
+                    io:format("calculated length ~p checksum ~p~n", [FileOffset2 - FileOffset, crypto:hash(sha256, binary:part(Data, 0, CommitLength))]),
+                    io:format("checksummed data: ~p~n", [binary:part(Data, 0, CommitLength)]),
+                    exit(assert);
+                CommitLength /= (FileOffset2 - FileOffset) ->
+                    io:format("length and offset mismatch~n", []),
+                    io:format("commit: length ~p checksum ~p~n", [CommitLength, CommitChecksum]),
+                    io:format("calculated length ~p checksum ~p~n", [FileOffset2 - FileOffset, crypto:hash(sha256, binary:part(Data, 0, CommitLength))]),
+                    io:format("checksummed data: ~p~n", [binary:part(Data, 0, CommitLength)]),
+                    exit(assert);
+                true ->
+                    ok
+            end,
+            printcommit(Rest, FileType, FileOffset3);
+        {ok, FileOffset2} ->
+            io:format("ending at offset ~p~n", [FileOffset]),
+            ok
+    end.
+
+printindex(<<>>, FileOffset) ->
+    {ok, FileOffset};
+printindex(<<?INDEX_NODE_COOKIE:64/native, Rest/binary>>, FileOffset) ->
+    FileOffset2 = FileOffset + 8,
+    Q = 2,
+    NChildren = 4,
+    ChildrenLength = NChildren * 8,
+    <<Children:ChildrenLength/binary, Rest2/binary>> = Rest,
+    io:format("node ~p~n", [FileOffset]),
+    printnode(Children),
+    printindex(Rest2, FileOffset2 + ChildrenLength);
+printindex(<<CommitLength:64/native, CommitChecksum:32/binary, ?INDEX_COMMIT_END_COOKIE:64/native, Rest/binary>>, FileOffset) ->
+    {{CommitLength, CommitChecksum, Rest}, FileOffset, FileOffset + 8 + 32 + 8};
+printindex(<<Unknown:16/binary, _Rest/binary>>, FileOffset) ->
+    io:format("unknown byte: ~p at ~p~n", [Unknown, FileOffset]),
+    error.
+
+printdata(<<>>, FileOffset) ->
+    {ok, FileOffset};
+printdata(<<?DATA_ENTRY_COOKIE:64, Key:32/binary, Length:32, Rest/binary>>, FileOffset) ->
+    FileOffset2 = FileOffset + 8 + 32 + 4,
+    io:format("data ~p key ~p length ~p~n", [FileOffset, Key, Length]),
+    <<Data:Length/binary, Rest2/binary>> = Rest,
+    printdata(Rest2, FileOffset2 + Length);
+printdata(<<?DATA_COMMIT_START_COOKIE:64, Rest2/binary>> = Rest, FileOffset) ->
+    Padding = case FileOffset rem 4 of
+        0 ->
+            0;
+        1 ->
+            3;
+        2 ->
+            2;
+        3 ->
+            1
+    end,
+    io:format("printdata: ~p ~p~n", [Padding, FileOffset]),
+    <<0:Padding/unit:8, CommitLength:32, CommitChecksum:32/binary, ?DATA_COMMIT_END_COOKIE:64, Rest3/binary>> = Rest2,
+    {{CommitLength, CommitChecksum, Rest3}, FileOffset + 8 + Padding + 4, FileOffset + 8 + Padding + 4 + 32 + 8};
+printdata(<<Unknown:16/binary, _Rest/binary>>, FileOffset) ->
+    io:format("unknown byte: ~p at ~p~n", [Unknown, FileOffset]),
+    error.
+
+main([Filename]) ->
+    {ok, FileInfo} = file:read_file_info(Filename),
+    File = openfile(Filename),
+    {ok, Data} = file:read(File, FileInfo#file_info.size),
+    io:format("read ~p bytes~n", [size(Data)]),
+    ok = printfile(Data),
+    ok.
-- 
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