1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/tools/diskutils.py	Sat Aug 09 18:27:13 2014 +0200
     1.3 @@ -0,0 +1,222 @@
     1.4 +"""
     1.5 +Copyright (C) 2014 David Boddie <david@boddie.org.uk>
     1.6 +
     1.7 +This program is free software: you can redistribute it and/or modify
     1.8 +it under the terms of the GNU General Public License as published by
     1.9 +the Free Software Foundation, either version 3 of the License, or
    1.10 +(at your option) any later version.
    1.11 +
    1.12 +This program is distributed in the hope that it will be useful,
    1.13 +but WITHOUT ANY WARRANTY; without even the implied warranty of
    1.14 +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    1.15 +GNU General Public License for more details.
    1.16 +
    1.17 +You should have received a copy of the GNU General Public License
    1.18 +along with this program.  If not, see <http://www.gnu.org/licenses/>.
    1.19 +"""
    1.20 +
    1.21 +import struct, time
    1.22 +
    1.23 +# Find the number of centiseconds between 1900 and 1970.
    1.24 +between_epochs = ((365 * 70) + 17) * 24 * 360000L
    1.25 +
    1.26 +class DiskError(Exception):
    1.27 +    pass
    1.28 +
    1.29 +
    1.30 +class Utilities:
    1.31 +
    1.32 +    # Little endian reading
    1.33 +    
    1.34 +    def _read_signed_word(self, s):
    1.35 +    
    1.36 +        return struct.unpack("<i", s)[0]
    1.37 +    
    1.38 +    def _read_unsigned_word(self, s):
    1.39 +    
    1.40 +        return struct.unpack("<I", s)[0]
    1.41 +    
    1.42 +    def _read_signed_byte(self, s):
    1.43 +    
    1.44 +        return struct.unpack("<b", s)[0]
    1.45 +    
    1.46 +    def _read_unsigned_byte(self, s):
    1.47 +    
    1.48 +        return struct.unpack("<B", s)[0]
    1.49 +    
    1.50 +    def _read_unsigned_half_word(self, s):
    1.51 +    
    1.52 +        return struct.unpack("<H", s)[0]
    1.53 +    
    1.54 +    def _read_signed_half_word(self, s):
    1.55 +    
    1.56 +        return struct.unpack("<h", s)[0]
    1.57 +    
    1.58 +    def _read(self, offset, length = 1):
    1.59 +    
    1.60 +        self.file.seek(offset, 0)
    1.61 +        return self.file.read(length)
    1.62 +    
    1.63 +    def _write_unsigned_word(self, v):
    1.64 +    
    1.65 +        return struct.pack("<I", v)
    1.66 +    
    1.67 +    def _write_unsigned_half_word(self, v):
    1.68 +    
    1.69 +        return struct.pack("<H", v)
    1.70 +    
    1.71 +    def _write_unsigned_byte(self, v):
    1.72 +    
    1.73 +        return struct.pack("<B", v)
    1.74 +    
    1.75 +    def _write(self, offset, data):
    1.76 +    
    1.77 +        self.file.seek(offset, 0)
    1.78 +        self.file.write(data)
    1.79 +    
    1.80 +    def _str2num(self, s):
    1.81 +    
    1.82 +        i = 0
    1.83 +        n = 0
    1.84 +        while i < len(s):
    1.85 +        
    1.86 +            n = n | (ord(s[i]) << (i*8))
    1.87 +            i = i + 1
    1.88 +        
    1.89 +        return n
    1.90 +    
    1.91 +    def _num2str(self, size, n):
    1.92 +    
    1.93 +        i = 0
    1.94 +        s = ""
    1.95 +        while i < size:
    1.96 +        
    1.97 +            s += chr(n & 0xff)
    1.98 +            n = n >> 8
    1.99 +            i += 1
   1.100 +        
   1.101 +        return s
   1.102 +    
   1.103 +    def _binary(self, size, n):
   1.104 +    
   1.105 +        new = ""
   1.106 +        while (n != 0) & (size > 0):
   1.107 +        
   1.108 +            if (n & 1)==1:
   1.109 +                new = "1" + new
   1.110 +            else:
   1.111 +                new = "0" + new
   1.112 +            
   1.113 +            n = n >> 1
   1.114 +            size = size - 1
   1.115 +        
   1.116 +        if size > 0:
   1.117 +            new = ("0"*size) + new
   1.118 +        
   1.119 +        return new
   1.120 +    
   1.121 +    def _safe(self, s, with_space = 0):
   1.122 +    
   1.123 +        new = ""
   1.124 +        if with_space == 1:
   1.125 +            lower = 31
   1.126 +        else:
   1.127 +            lower = 32
   1.128 +        
   1.129 +        for c in s:
   1.130 +        
   1.131 +            if ord(c) >= 128:
   1.132 +                i = ord(c) ^ 128
   1.133 +                c = chr(i)
   1.134 +            
   1.135 +            if ord(c) <= lower:
   1.136 +                break
   1.137 +            
   1.138 +            new = new + c
   1.139 +        
   1.140 +        return new
   1.141 +    
   1.142 +    def _pad(self, s, length, ch):
   1.143 +    
   1.144 +        s = s[:length]
   1.145 +        if len(s) < length:
   1.146 +            s += (length - len(s)) * ch
   1.147 +        
   1.148 +        return s
   1.149 +
   1.150 +
   1.151 +class Directory:
   1.152 +
   1.153 +    """directory = Directory(name, address)
   1.154 +    
   1.155 +    The directory created contains name and files attributes containing the
   1.156 +    directory name and the objects it contains.
   1.157 +    """
   1.158 +    
   1.159 +    def __init__(self, name, files):
   1.160 +    
   1.161 +        self.name = name
   1.162 +        self.files = files
   1.163 +    
   1.164 +    def __repr__(self):
   1.165 +    
   1.166 +        return '<%s instance, "%s", at %x>' % (self.__class__, self.name, id(self))
   1.167 +
   1.168 +
   1.169 +class File:
   1.170 +
   1.171 +    """file = File(name, data, load_address, execution_address, length)
   1.172 +    """
   1.173 +    
   1.174 +    def __init__(self, name, data, load_address, execution_address, length,
   1.175 +                       locked = False, disk_address = 0):
   1.176 +    
   1.177 +        self.name = name
   1.178 +        self.data = data
   1.179 +        self.load_address = load_address
   1.180 +        self.execution_address = execution_address
   1.181 +        self.length = length
   1.182 +        self.locked = locked
   1.183 +        self.disk_address = disk_address
   1.184 +    
   1.185 +    def __repr__(self):
   1.186 +    
   1.187 +        return '<%s instance, "%s", at %x>' % (self.__class__, self.name, id(self))
   1.188 +    
   1.189 +    def has_filetype(self):
   1.190 +    
   1.191 +        """Returns True if the file's meta-data contains filetype information."""
   1.192 +        return self.load_address & 0xfff00000 == 0xfff00000
   1.193 +    
   1.194 +    def filetype(self):
   1.195 +    
   1.196 +        """Returns the meta-data containing the filetype information.
   1.197 +        
   1.198 +        Note that a filetype can be obtained for all files, though it may not
   1.199 +        necessarily be valid. Use has_filetype() to determine whether the file
   1.200 +        is likely to have a valid filetype."""
   1.201 +        
   1.202 +        return "%03x" % ((self.load_address >> 8) & 0xfff)
   1.203 +    
   1.204 +    def time_stamp(self):
   1.205 +    
   1.206 +        """Returns the time stamp for the file as a tuple of values containing
   1.207 +        the local time, or an empty tuple if the file does not have a time stamp."""
   1.208 +        
   1.209 +        # RISC OS time is given as a five byte block containing the
   1.210 +        # number of centiseconds since 1900 (presumably 1st January 1900).
   1.211 +        
   1.212 +        # Convert the time to the time elapsed since the Epoch (assuming
   1.213 +        # 1970 for this value).
   1.214 +        date_num = struct.unpack("<Q",
   1.215 +            struct.pack("<IBxxx", self.execution_address, self.load_address & 0xff))[0]
   1.216 +        
   1.217 +        centiseconds = date_num - between_epochs
   1.218 +        
   1.219 +        # Convert this to a value in seconds and return a time tuple.
   1.220 +        try:
   1.221 +            return time.localtime(centiseconds / 100.0)
   1.222 +        except ValueError:
   1.223 +            return ()
   1.224 +
   1.225 +