Current File : //lib/calibre/calibre/ebooks/__init__.py
__license__ = 'GPL v3'
__copyright__ = '2008, Kovid Goyal <kovid at kovidgoyal.net>'
'''
Code for the conversion of ebook formats and the reading of metadata
from various formats.
'''
import os, re, numbers, sys
from calibre import prints
from calibre.ebooks.chardet import xml_to_unicode
class ConversionError(Exception):
def __init__(self, msg, only_msg=False):
Exception.__init__(self, msg)
self.only_msg = only_msg
class UnknownFormatError(Exception):
pass
class DRMError(ValueError):
pass
class ParserError(ValueError):
pass
BOOK_EXTENSIONS = ['lrf', 'rar', 'zip', 'rtf', 'lit', 'txt', 'txtz', 'text', 'htm', 'xhtm',
'html', 'htmlz', 'xhtml', 'pdf', 'pdb', 'updb', 'pdr', 'prc', 'mobi', 'azw', 'doc',
'epub', 'fb2', 'fbz', 'djv', 'djvu', 'lrx', 'cbr', 'cb7', 'cbz', 'cbc', 'oebzip',
'rb', 'imp', 'odt', 'chm', 'tpz', 'azw1', 'pml', 'pmlz', 'mbp', 'tan', 'snb',
'xps', 'oxps', 'azw4', 'book', 'zbf', 'pobi', 'docx', 'docm', 'md',
'textile', 'markdown', 'ibook', 'ibooks', 'iba', 'azw3', 'ps', 'kepub', 'kfx', 'kpf']
def return_raster_image(path):
from calibre.utils.imghdr import what
if os.access(path, os.R_OK):
with open(path, 'rb') as f:
raw = f.read()
if what(None, raw) not in (None, 'svg'):
return raw
def extract_cover_from_embedded_svg(html, base, log):
from calibre.ebooks.oeb.base import XPath, SVG, XLINK
from calibre.utils.xml_parse import safe_xml_fromstring
root = safe_xml_fromstring(html)
svg = XPath('//svg:svg')(root)
if len(svg) == 1 and len(svg[0]) == 1 and svg[0][0].tag == SVG('image'):
image = svg[0][0]
href = image.get(XLINK('href'), None)
if href:
path = os.path.join(base, *href.split('/'))
return return_raster_image(path)
def extract_calibre_cover(raw, base, log):
from calibre.ebooks.BeautifulSoup import BeautifulSoup
soup = BeautifulSoup(raw)
matches = soup.find(name=['h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'p', 'span',
'font', 'br'])
images = soup.findAll('img', src=True)
if matches is None and len(images) == 1 and \
images[0].get('alt', '').lower()=='cover':
img = images[0]
img = os.path.join(base, *img['src'].split('/'))
q = return_raster_image(img)
if q is not None:
return q
# Look for a simple cover, i.e. a body with no text and only one <img> tag
if matches is None:
body = soup.find('body')
if body is not None:
text = ''.join(map(str, body.findAll(text=True)))
if text.strip():
# Body has text, abort
return
images = body.findAll('img', src=True)
if len(images) == 1:
img = os.path.join(base, *images[0]['src'].split('/'))
return return_raster_image(img)
def render_html_svg_workaround(path_to_html, log, width=590, height=750):
from calibre.ebooks.oeb.base import SVG_NS
with open(path_to_html, 'rb') as f:
raw = f.read()
raw = xml_to_unicode(raw, strip_encoding_pats=True)[0]
data = None
if SVG_NS in raw:
try:
data = extract_cover_from_embedded_svg(raw,
os.path.dirname(path_to_html), log)
except Exception:
pass
if data is None:
try:
data = extract_calibre_cover(raw, os.path.dirname(path_to_html), log)
except Exception:
pass
if data is None:
data = render_html_data(path_to_html, width, height)
return data
def render_html_data(path_to_html, width, height):
from calibre.ptempfile import TemporaryDirectory
from calibre.utils.ipc.simple_worker import fork_job, WorkerError
result = {}
def report_error(text=''):
prints('Failed to render', path_to_html, 'with errors:', file=sys.stderr)
if text:
prints(text, file=sys.stderr)
if result and result['stdout_stderr']:
with open(result['stdout_stderr'], 'rb') as f:
prints(f.read(), file=sys.stderr)
with TemporaryDirectory('-render-html') as tdir:
try:
result = fork_job('calibre.ebooks.render_html', 'main', args=(path_to_html, tdir, 'jpeg'))
except WorkerError as e:
report_error(e.orig_tb)
else:
if result['result']:
with open(os.path.join(tdir, 'rendered.jpeg'), 'rb') as f:
return f.read()
else:
report_error()
def check_ebook_format(stream, current_guess):
ans = current_guess
if current_guess.lower() in ('prc', 'mobi', 'azw', 'azw1', 'azw3'):
stream.seek(0)
if stream.read(3) == b'TPZ':
ans = 'tpz'
stream.seek(0)
return ans
def normalize(x):
if isinstance(x, str):
import unicodedata
x = unicodedata.normalize('NFC', x)
return x
def calibre_cover(title, author_string, series_string=None,
output_format='jpg', title_size=46, author_size=36, logo_path=None):
title = normalize(title)
author_string = normalize(author_string)
series_string = normalize(series_string)
from calibre.ebooks.covers import calibre_cover2
from calibre.utils.img import image_to_data
ans = calibre_cover2(title, author_string or '', series_string or '', logo_path=logo_path, as_qimage=True)
return image_to_data(ans, fmt=output_format)
UNIT_RE = re.compile(r'^(-*[0-9]*[.]?[0-9]*)\s*(%|em|ex|en|px|mm|cm|in|pt|pc|rem|q)$')
def unit_convert(value, base, font, dpi, body_font_size=12):
' Return value in pts'
if isinstance(value, numbers.Number):
return value
try:
return float(value) * 72.0 / dpi
except:
pass
result = value
m = UNIT_RE.match(value)
if m is not None and m.group(1):
value = float(m.group(1))
unit = m.group(2)
if unit == '%':
result = (value / 100.0) * base
elif unit == 'px':
result = value * 72.0 / dpi
elif unit == 'in':
result = value * 72.0
elif unit == 'pt':
result = value
elif unit == 'em':
result = value * font
elif unit in ('ex', 'en'):
# This is a hack for ex since we have no way to know
# the x-height of the font
font = font
result = value * font * 0.5
elif unit == 'pc':
result = value * 12.0
elif unit == 'mm':
result = value * 2.8346456693
elif unit == 'cm':
result = value * 28.346456693
elif unit == 'rem':
result = value * body_font_size
elif unit == 'q':
result = value * 0.708661417325
return result
def parse_css_length(value):
try:
m = UNIT_RE.match(value)
except TypeError:
return None, None
if m is not None and m.group(1):
value = float(m.group(1))
unit = m.group(2)
return value, unit.lower()
return None, None
def generate_masthead(title, output_path=None, width=600, height=60):
from calibre.ebooks.conversion.config import load_defaults
recs = load_defaults('mobi_output')
masthead_font_family = recs.get('masthead_font', None)
from calibre.ebooks.covers import generate_masthead
return generate_masthead(title, output_path=output_path, width=width, height=height, font_family=masthead_font_family)
def escape_xpath_attr(value):
if '"' in value:
if "'" in value:
parts = re.split('("+)', value)
ans = []
for x in parts:
if x:
q = "'" if '"' in x else '"'
ans.append(q + x + q)
return 'concat(%s)' % ', '.join(ans)
else:
return "'%s'" % value
return '"%s"' % value
Mini Shell