lrdp-v2: refactor dmesg extraction code

It can be useful to extract the dmesg from contexts other than the
--dmesg parser. Refactor the code into a top-level "library" module and
hook the --dmesg parser into that.

Change-Id: I935c05a081b1096d67343f5ce8617febb674b2e0

linux-ramdump-parser-v2/dmesglib.py

+# Copyright (c) 2014, The Linux Foundation. All rights reserved.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 and
+# only version 2 as published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+import re
+import string
+
+from parser_util import cleanupString
+
+class DmesgLib(object):
+
+    def __init__(self, ramdump, outfile):
+        self.ramdump = ramdump
+        self.wrap_cnt = 0
+        self.outfile = outfile
+
+    def log_from_idx(self, idx, logbuf):
+        len_offset = self.ramdump.field_offset('struct log', 'len')
+
+        msg = logbuf + idx
+        msg_len = self.ramdump.read_u16(msg + len_offset)
+        if (msg_len == 0):
+            return logbuf
+        else:
+            return msg
+
+    def log_next(self, idx, logbuf):
+        len_offset = self.ramdump.field_offset('struct log', 'len')
+        msg = idx
+
+        msg_len = self.ramdump.read_u16(msg + len_offset)
+        if (msg_len == 0):
+            self.wrap_cnt += 1
+            return logbuf
+        else:
+            return idx + msg_len
+
+    def extract_dmesg_flat(self):
+        addr = self.ramdump.read_word(self.ramdump.addr_lookup('log_buf'))
+        size = self.ramdump.read_word(self.ramdump.addr_lookup('log_buf_len'))
+        dmesg = self.ramdump.read_physical(self.ramdump.virt_to_phys(addr), size)
+        self.outfile.write(cleanupString(dmesg.decode('ascii', 'ignore')) + '\n')
+
+    def extract_dmesg_binary(self):
+        first_idx_addr = self.ramdump.addr_lookup('log_first_idx')
+        last_idx_addr = self.ramdump.addr_lookup('log_next_idx')
+        logbuf_addr = self.ramdump.read_word(self.ramdump.addr_lookup('log_buf'))
+        time_offset = self.ramdump.field_offset('struct log', 'ts_nsec')
+        len_offset = self.ramdump.field_offset('struct log', 'len')
+        text_len_offset = self.ramdump.field_offset('struct log', 'text_len')
+        log_size = self.ramdump.sizeof('struct log')
+
+        first_idx = self.ramdump.read_u32(first_idx_addr)
+        last_idx = self.ramdump.read_u32(last_idx_addr)
+
+        curr_idx = logbuf_addr + first_idx
+
+        while curr_idx != logbuf_addr + last_idx and self.wrap_cnt < 2:
+            timestamp = self.ramdump.read_dword(curr_idx + time_offset)
+            text_len = self.ramdump.read_u16(curr_idx + text_len_offset)
+            text_str = self.ramdump.read_cstring(curr_idx + log_size, text_len)
+            for partial in text_str.split('\n'):
+                f = '[{0:>5}.{1:0>6d}] {2}\n'.format(
+                    timestamp / 1000000000, (timestamp % 1000000000) / 1000, partial)
+                self.outfile.write(f)
+            curr_idx = self.log_next(curr_idx, logbuf_addr)
+
+    def extract_dmesg(self):
+        if re.search('3.7.\d', self.ramdump.version) is not None:
+            self.extract_dmesg_binary()
+        elif re.search('3\.10\.\d', self.ramdump.version) is not None:
+            self.extract_dmesg_binary()
+        else:
+            self.extract_dmesg_flat()

linux-ramdump-parser-v2/parsers/dmesg.py

@@ -9,75 +9,12 @@
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 
-import re
-import string
-
-from print_out import print_out_str
-from parser_util import register_parser, RamParser, cleanupString
-
+from parser_util import register_parser, RamParser
+import print_out
+import dmesglib
 
 @register_parser('--dmesg', 'Print the dmesg', shortopt='-d')
 class Dmesg(RamParser):
 
-    def __init__(self, *args):
-        super(Dmesg, self).__init__(*args)
-        self.wrap_cnt = 0
-
-    def extract_dmesg_flat(self, ramdump):
-        addr = ramdump.read_word(ramdump.addr_lookup('log_buf'))
-        size = ramdump.read_word(ramdump.addr_lookup('log_buf_len'))
-        dmesg = ramdump.read_physical(ramdump.virt_to_phys(addr), size)
-        print_out_str(cleanupString(dmesg.decode('ascii', 'ignore')))
-
-    def log_from_idx(self, ramdump, idx, logbuf):
-        len_offset = ramdump.field_offset('struct log', 'len')
-
-        msg = logbuf + idx
-        msg_len = ramdump.read_u16(msg + len_offset)
-        if (msg_len == 0):
-            return logbuf
-        else:
-            return msg
-
-    def log_next(self, ramdump, idx, logbuf):
-        len_offset = ramdump.field_offset('struct log', 'len')
-        msg = idx
-
-        msg_len = ramdump.read_u16(msg + len_offset)
-        if (msg_len == 0):
-            self.wrap_cnt += 1
-            return logbuf
-        else:
-            return idx + msg_len
-
-    def extract_dmesg_binary(self, ramdump):
-        first_idx_addr = ramdump.addr_lookup('log_first_idx')
-        last_idx_addr = ramdump.addr_lookup('log_next_idx')
-        logbuf_addr = ramdump.read_word(ramdump.addr_lookup('log_buf'))
-        time_offset = ramdump.field_offset('struct log', 'ts_nsec')
-        len_offset = ramdump.field_offset('struct log', 'len')
-        text_len_offset = ramdump.field_offset('struct log', 'text_len')
-        log_size = ramdump.sizeof('struct log')
-
-        first_idx = ramdump.read_u32(first_idx_addr)
-        last_idx = ramdump.read_u32(last_idx_addr)
-
-        curr_idx = logbuf_addr + first_idx
-
-        while curr_idx != logbuf_addr + last_idx and self.wrap_cnt < 2:
-            timestamp = ramdump.read_dword(curr_idx + time_offset)
-            text_len = ramdump.read_u16(curr_idx + text_len_offset)
-            text_str = ramdump.read_cstring(curr_idx + log_size, text_len)
-            for partial in text_str.split('\n'):
-                f = '[{0:>5}.{1:0>6d}] {2}'.format(
-                    timestamp / 1000000000, (timestamp % 1000000000) / 1000, partial)
-                print_out_str(f)
-            curr_idx = self.log_next(ramdump, curr_idx, logbuf_addr)
-
     def parse(self):
-        if re.search('3.7.\d', self.ramdump.version) is not None:
-            self.extract_dmesg_binary(self.ramdump)
-        elif re.search('3\.10\.\d', self.ramdump.version) is not None:
-            self.extract_dmesg_binary(self.ramdump)
-        else:
-            self.extract_dmesg_flat(self.ramdump)
+        dmesglib.DmesgLib(self.ramdump, print_out.out_file).extract_dmesg()