Class: FastLib

Inherits:
Object
  • Object
show all
Defined in:
lib/fastlib.rb

Overview

The FastLib class implements the meat of the FASTLIB archive format

Constant Summary collapse

VERSION = 
"0.0.8"
FLAG_COMPRESS = 
0x01
FLAG_ENCRYPT = 
0x02
@@cache = 
{}
@@has_zlib = 
false

Class Method Summary collapse

Class Method Details

.cache ⇒ Object

Expose the cache to callers



273
274
275
 
# File 'lib/fastlib.rb', line 273

def self.cache
	@@cache
end

.create(lib, flags, bdir, *dirs) ⇒ Object

This method provides a way to create a FASTLIB archive programatically, the key arguments are the name of the destination archive, the base directory that should be excluded from the archived path, and finally the list of specific files and directories to include in the archive.



182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
 
# File 'lib/fastlib.rb', line 182

def self.create(lib, flags, bdir, *dirs)
	head = ""
	data = ""
	hidx = 0
	didx = 0
	
	bdir = bdir.gsub(/\/$/, '')
	brex = /^#{Regexp.escape(bdir)}\//
	
	if flags.kind_of?(::String)
		if flags =~ /^0x/
			flags = flags.to_i(16)
		else
			flags = flags.to_i
		end
	end

	@@cache[lib] = {
		:fastlib_flags => flags
	}
	
	dirs.each do |dir|
		::Find.find(dir).each do |path|
			next if not ::File.file?(path)
			name = fastlib_filter_encode( lib, path.sub( brex, "" ) )
			
			buff = ""
			::File.open(path, "rb") do |fd|
				buff = fastlib_filter_encode(lib, fd.read(fd.stat.size))
			end
			
			head << [ name.length, didx, buff.length, ::File.stat(path).mtime.utc.to_i ].pack("NNNN")
			head << name
			hidx = hidx + 16 + name.length
		
			data << buff
			didx = didx + buff.length
		end
	end
	
	head << [0,0,0].pack("NNN")
	
	::File.open(lib, "wb") do |fd|
		fd.write("FAST")
		fd.write( [ head.length, flags ].pack("NN") )
		fd.write( head )
		fd.write( data )
	end	
end

.decrypt_00000000(data) ⇒ Object 



266
267
268
 
# File 'lib/fastlib.rb', line 266

def self.decrypt_00000000(data)
	encrypt_00000000(data)
end

.decrypt_12345600(data) ⇒ Object 



258
259
260
 
# File 'lib/fastlib.rb', line 258

def self.decrypt_12345600(data)
	encrypt_00000000(data)
end

.encrypt_00000000(data) ⇒ Object 



262
263
264
 
# File 'lib/fastlib.rb', line 262

def self.encrypt_00000000(data)
	data.unpack("C*").map{ |c| c ^ 0x90 }.pack("C*")
end

.encrypt_12345600(data) ⇒ Object

This is a stub crypto handler that performs a basic XOR operation against a fixed one byte key. The two usable IDs are 12345600 and 00000000



254
255
256
 
# File 'lib/fastlib.rb', line 254

def self.encrypt_12345600(data)
	encrypt_00000000(data)
end

.fastlib_filter_decode(lib, buff) ⇒ Object

This method provides compression and encryption capabilities for the fastlib archive format.



119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
 
# File 'lib/fastlib.rb', line 119

def self.fastlib_filter_decode(lib, buff)

	if (@@cache[lib][:fastlib_flags] & FLAG_ENCRYPT) != 0
	
		@@cache[lib][:fastlib_decrypt] ||= ::Proc.new do |data|
			stub = "decrypt_%.8x" % ( @@cache[lib][:fastlib_flags] & 0xfffffff0 )
			FastLib.send(stub, data)
		end

		buff = @@cache[lib][:fastlib_decrypt].call( buff )
	end
	
	if (@@cache[lib][:fastlib_flags] & FLAG_COMPRESS) != 0
		if not @@has_zlib
			raise ::RuntimeError, "zlib is required to open this archive"
		end

		z = Zlib::Inflate.new
		buff = z.inflate(buff)
		buff << z.finish
		z.close	
	end
	
	buff
end

.fastlib_filter_encode(lib, buff) ⇒ Object

This method provides compression and encryption capabilities for the fastlib archive format.



149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
 
# File 'lib/fastlib.rb', line 149

def self.fastlib_filter_encode(lib, buff)
	
	if (@@cache[lib][:fastlib_flags] & FLAG_COMPRESS) != 0
		if not @@has_zlib
			raise ::RuntimeError, "zlib is required to open this archive"
		end

		z = Zlib::Deflate.new
		buff = z.deflate(buff)
		buff << z.finish
		z.close	
	end

	if (@@cache[lib][:fastlib_flags] & FLAG_ENCRYPT) != 0
	
		@@cache[lib][:fastlib_encrypt] ||= ::Proc.new do |data|
			stub = "encrypt_%.8x" % ( @@cache[lib][:fastlib_flags] & 0xfffffff0 )
			FastLib.send(stub, data)
		end

		buff = @@cache[lib][:fastlib_encrypt].call( buff )
	end
	
	buff
end

.list(lib) ⇒ Object

This method provides a way to list the contents of an archive file, returning the names only in sorted order.



236
237
238
239
 
# File 'lib/fastlib.rb', line 236

def self.list(lib)
	load_cache(lib)
	( @@cache[lib] || {} ).keys.map{|x| x.to_s }.sort.select{ |x| @@cache[lib][x] }
end

.load(lib, name, noprocess = false) ⇒ Object

This method loads content from a specific archive file by name. If the noprocess argument is set to true, the contents will not be expanded to include workarounds for things such as __FILE__. This is useful when loading raw binary data where these strings may occur



62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
 
# File 'lib/fastlib.rb', line 62

def self.load(lib, name, noprocess=false)
	data = ""
	load_cache(lib)

	return if not ( @@cache[lib] and @@cache[lib][name] )
	
	
	::File.open(lib, "rb") do |fd|
		fd.seek(
			@@cache[lib][:fastlib_header][0] +
			@@cache[lib][:fastlib_header][1] + 
			@@cache[lib][name][0]
		)
		data = fastlib_filter_decode( lib, fd.read(@@cache[lib][name][1] ))
	end
	
	# Return the contents in raw or processed form
	noprocess ? data : post_process(lib, name, data)
end

.load_cache(lib) ⇒ Object

This method caches the file list and offsets within the archive



85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
 
# File 'lib/fastlib.rb', line 85

def self.load_cache(lib)
	return if @@cache[lib]
	@@cache[lib] = {}
	
	return if not ::File.exists?(lib)
			
	::File.open(lib, 'rb') do |fd|
		dict = {}
		head = fd.read(4)
		return if head != "FAST"
		hlen = fd.read(4).unpack("N")[0]
		flag = fd.read(4).unpack("N")[0]			
	
		@@cache[lib][:fastlib_header] = [12, hlen, fd.stat.mtime.utc.to_i ]
		@@cache[lib][:fastlib_flags]  = flag
		
		nlen, doff, dlen, tims = fd.read(16).unpack("N*")
		
		while nlen > 0
			name = fastlib_filter_decode( lib, fd.read(nlen) )
			dict[name] = [doff, dlen, tims]
			
			nlen, doff, dlen, tims = fd.read(16).unpack("N*")
		end
		
		@@cache[lib].merge!(dict)
	end
	
end

.post_process(lib, name, data) ⇒ Object

This method is expands __FILE__ sequences and other inline dynamic constants to map to the correct location.



245
246
247
 
# File 'lib/fastlib.rb', line 245

def self.post_process(lib, name, data)
	data.gsub('__FILE__', "'#{ ::File.expand_path(::File.join(::File.dirname(lib), name)) }'")
end

.version ⇒ Object

This method returns the version of the fastlib library



52
53
54
 
# File 'lib/fastlib.rb', line 52

def self.version
	VERSION
end