1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
|
const std = @import("std");
const varint = @import("varint.zig");
const record = @import("record.zig");
pub fn showTables(allocator: std.mem.Allocator, file: *std.fs.File, page_size: u16, stdout: anytype) !void {
var buf: [2]u8 = undefined;
_ = try file.seekTo(103);
_ = try file.read(&buf);
const num_cells = std.mem.readInt(u16, &buf, .big);
var cell_pointers = try allocator.alloc(u16, num_cells);
defer allocator.free(cell_pointers);
for (0..num_cells) |i| {
_ = try file.seekTo(108 + i * 2);
_ = try file.read(&buf);
cell_pointers[i] = std.mem.readInt(u16, &buf, .big);
}
var page_data = try allocator.alloc(u8, page_size);
defer allocator.free(page_data);
_ = try file.seekTo(0);
_ = try file.read(page_data);
var first = true;
for (0..num_cells) |i| {
const cell_data = page_data[cell_pointers[i]..];
var parsed = varint.parse(cell_data);
var pos = parsed.len;
parsed = varint.parse(cell_data[pos..]);
pos += parsed.len;
const record_data = cell_data[pos..];
parsed = varint.parse(record_data);
const header_size = parsed.value;
var header_pos = parsed.len;
var serial_types: [5]u64 = undefined;
for (0..5) |col| {
parsed = varint.parse(record_data[header_pos..]);
serial_types[col] = parsed.value;
header_pos += parsed.len;
}
var body_pos: usize = header_size;
for (0..2) |col| {
const st = serial_types[col];
if (st >= 13 and (st % 2) == 1) {
body_pos += (st - 13) / 2;
}
}
const type_result = record.readString(record_data[header_size..], serial_types[0]);
const tbl_name = record.readString(record_data[body_pos..], serial_types[2]);
if (std.mem.eql(u8, type_result.value, "table") and !std.mem.eql(u8, tbl_name.value, "sqlite_sequence")) {
if (!first) try stdout.print(" ", .{});
try stdout.print("{s}", .{tbl_name.value});
first = false;
}
}
if (!first) try stdout.print("\n", .{});
}
|
