layout2dot source code

1 module layout2dot;
2 import sqlited;
3 import utils;
4 import std.conv : to;
5 import misc;
6 
7 string TreeLayoutToDot(Database db) {
8 	string result = "digraph table {";
9 
10 	Database.MasterTableSchema[] schemas;
11 	schemas = readRows!(r => r.deserialize!(Database.MasterTableSchema))(db.rootPage,
12 		db.pages);
13 	result ~= TreeLayoutToDot(db.rootPage, db.pages, 1);
14 	foreach (schema; schemas) {
15 		if (schema.rootPage) {
16 			result ~= "\n" ~ "\"Root\"" ~ " -> " ~ '"' ~ toQuotedString(schema.rootPage) ~ '"' ~ "\n";
17 			result ~= TreeLayoutToDot(db.pages[schema.rootPage - 1], db.pages, schema.rootPage) ~ "\n";
18 		}
19 	}
20 
21 	return result ~ "}\n";
22 }
23 
24 string toQuotedString(uint i) {
25 	return "\"" ~ to!string(i) ~ "\"";
26 }
27 
28 string TreeLayoutToDot(Database.BTreePage page, Database.PageRange pages, uint rootPage) {
29 	string pref = "\n" ~ toQuotedString(rootPage) ~ " -> ";
30 	string result;
31 	auto cpa = page.getCellPointerArray();
32 
33 	switch (page.pageType) {
34 	case Database.BTreePageType.tableInteriorPage: {
35 			foreach (cp; cpa) {
36 				uint nextPage = BigEndian!uint(page.page[cp .. cp + uint.sizeof]);
37 				result ~= pref ~ toQuotedString(nextPage);
38 				result ~= TreeLayoutToDot(pages[nextPage - 1], pages, nextPage);
39 			}
40 
41 			uint nextPage = page.header._rightmostPointer;
42 			result ~= pref ~ toQuotedString(nextPage);
43 			result ~= TreeLayoutToDot(pages[nextPage - 1], pages, nextPage);
44 		}
45 		break;
46 	case Database.BTreePageType.tableLeafPage: {
47 
48 		}
49 		break;
50 	default: {
51 		}
52 
53 	}
54 	return result;
55 }