From 5b8974dbb1680e1ea796c884acc2e8d413fb0b10 Mon Sep 17 00:00:00 2001
From: John Schember <john@nachtimwald.com>
Date: Sun, 3 May 2009 18:44:09 -0400
Subject: [PATCH] PDB ztxt writer.

---
 src/calibre/ebooks/pdb/__init__.py       |  4 +-
 src/calibre/ebooks/pdb/palmdoc/writer.py |  2 +-
 src/calibre/ebooks/pdb/ztxt/writer.py    | 78 ++++++++++++++++++++++++
 3 files changed, 82 insertions(+), 2 deletions(-)
 create mode 100644 src/calibre/ebooks/pdb/ztxt/writer.py

diff --git a/src/calibre/ebooks/pdb/__init__.py b/src/calibre/ebooks/pdb/__init__.py
index f60cc91c93..70a12ceb96 100644
--- a/src/calibre/ebooks/pdb/__init__.py
+++ b/src/calibre/ebooks/pdb/__init__.py
@@ -21,9 +21,11 @@ FORMAT_READERS = {
 }
 
 from calibre.ebooks.pdb.palmdoc.writer import Writer as palmdoc_writer
+from calibre.ebooks.pdb.ztxt.writer import Writer as ztxt_writer
 
 FORMAT_WRITERS = {
-    'doc' : palmdoc_writer,
+    'doc'  : palmdoc_writer,
+    'ztxt' : ztxt_writer,
 }
 
 IDENTITY_TO_NAME = {
diff --git a/src/calibre/ebooks/pdb/palmdoc/writer.py b/src/calibre/ebooks/pdb/palmdoc/writer.py
index a93bc94d26..705b01daee 100644
--- a/src/calibre/ebooks/pdb/palmdoc/writer.py
+++ b/src/calibre/ebooks/pdb/palmdoc/writer.py
@@ -34,7 +34,7 @@ class Writer(FormatWriter):
             txt_records[i] = compress_doc(txt_records[i].encode('utf-8'))
             section_lengths.append(len(txt_records[i]))
             
-        out_stream.seek(0)            
+        out_stream.seek(0)
         hb = PdbHeaderBuilder('TEXtREAd', title)
         hb.build_header(section_lengths, out_stream)
         
diff --git a/src/calibre/ebooks/pdb/ztxt/writer.py b/src/calibre/ebooks/pdb/ztxt/writer.py
new file mode 100644
index 0000000000..81a0df48af
--- /dev/null
+++ b/src/calibre/ebooks/pdb/ztxt/writer.py
@@ -0,0 +1,78 @@
+# -*- coding: utf-8 -*-
+
+'''
+Writer content to ztxt pdb file.
+'''
+
+__license__   = 'GPL v3'
+__copyright__ = '2009, John Schember <john@nachtimwald.com>'
+__docformat__ = 'restructuredtext en'
+
+import struct, zlib
+
+from calibre.ebooks.pdb.formatwriter import FormatWriter
+from calibre.ebooks.txt.writer import TxtWriter, TxtNewlines, TxtMetadata
+from calibre.ebooks.pdb.header import PdbHeaderBuilder
+
+MAX_RECORD_SIZE = 8192
+
+class Writer(FormatWriter):
+
+    def __init__(self, opts, log):
+        self.opts = opts
+        self.log = log
+        
+    def write_content(self, oeb_book, out_stream):
+        title = self.opts.title if self.opts.title else oeb_book.metadata.title[0].value if oeb_book.metadata.title != [] else _('Unknown')
+
+        txt_records, txt_length = self._generate_text(oeb_book.spine)
+        
+        crc32 = 0
+        section_lengths = []
+        compressor = zlib.compressobj(9)
+        for i in range(0, len(txt_records)):
+            txt_records[i] = compressor.compress(txt_records[i].encode('utf-8'))
+            txt_records[i] = txt_records[i] + compressor.flush(zlib.Z_FULL_FLUSH)
+            section_lengths.append(len(txt_records[i]))
+            crc32 = zlib.crc32(txt_records[i], crc32) & 0xffffffff
+
+        header_record = self._header_record(txt_length, len(txt_records), crc32)
+        section_lengths.insert(0, len(header_record))
+            
+        out_stream.seek(0)
+        hb = PdbHeaderBuilder('zTXTGPlm', title)
+        hb.build_header(section_lengths, out_stream)
+
+        for record in [header_record]+txt_records:
+            out_stream.write(record)
+        
+    def _generate_text(self, spine):
+        txt_writer = TxtWriter(TxtNewlines('system').newline, self.log)
+        txt = txt_writer.dump(spine, TxtMetadata())
+        
+        txt_length = len(txt)
+        
+        txt_records = []
+        for i in range(0, (len(txt) / MAX_RECORD_SIZE) + 1):
+            txt_records.append(txt[i * MAX_RECORD_SIZE : (i * MAX_RECORD_SIZE) + MAX_RECORD_SIZE])
+            
+        return txt_records, txt_length
+        
+    def _header_record(self, txt_length, record_count, crc32):
+        record = ''
+        
+        record += struct.pack('>H', 0x012c)             # [0:2], version. 0x012c = 1.44
+        record += struct.pack('>H', record_count)       # [2:4], Number of PDB records used for the text of the book.
+        record += struct.pack('>L', txt_length)         # [4:8], Uncompressed length of the entire text of the book.
+        record += struct.pack('>H', MAX_RECORD_SIZE)    # [8:10], Maximum size of each record containing text
+        record += struct.pack('>H', 0)                  # [10:12], Number of bookmarks.
+        record += struct.pack('>H', 0)                  # [12:14], Bookmark record. 0 if there are no bookmarks.
+        record += struct.pack('>H', 0)                  # [14:16], Number of annotations.
+        record += struct.pack('>H', 0)                  # [16:18], Annotation record. 0 if there are no annotations.
+        record += struct.pack('>B', 1)                  # [18:19], Flags. Bitmask, 0x01 = Random Access. 0x02 = Non-Uniform text block size.
+        record += struct.pack('>B', 0)                  # [19:20], Reserved.
+        record += struct.pack('>L', crc32)              # [20:24], crc32
+        record += struct.pack('>LL', 0, 0)              # [24:32], padding
+        
+        return record
+