# Copyright (C) 2009, 2010  Roman Zimbelmann <romanz@lavabit.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# 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.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

class Bar(object):
	left = None
	right = None
	gap = None

	def __init__(self, base_color_tag):
		self.left = BarSide(base_color_tag)
		self.rightpre { line-height: 125%; }
td.linenos .normal { color: inherit; background-color: transparent; padding-left: 5px; padding-right: 5px; }
span.linenos { color: inherit; background-color: transparent; padding-left: 5px; padding-right: 5px; }
td.linenos .special { color: #000000; background-color: #ffffc0; padding-left: 5px; padding-right: 5px; }
span.linenos.special { color: #000000; background-color: #ffffc0; padding-left: 5px; padding-right: 5px; }
.highlight .hll { background-color: #ffffcc }
.highlight .c { color: #888888 } /* Comment */
.highlight .err { color: #a61717; background-color: #e3d2d2 } /* Error */
.highlight .k { color: #008800; font-weight: bold } /* Keyword */
.highlight .ch { color: #888888 } /* Comment.Hashbang */
.highlight .cm { color: #888888 } /* Comment.Multiline */
.highlight .cp { color: #cc0000; font-weight: bold } /* Comment.Preproc */
.highlight .cpf { color: #888888 } /* Comment.PreprocFile */
.highlight .c1 { color: #888888 } /* Comment.Single */
.highlight .cs { color: #cc0000; font-weight: bold; background-color: #fff0f0 } /* Comment.Special */
.highlight .gd { color: #000000; background-color: #ffdddd } /* Generic.Deleted */
.highlight .ge { font-style: italic } /* Generic.Emph */
.highlight .ges { font-weight: bold; font-style: italic } /* Generic.EmphStrong */
.highlight .gr { color: #aa0000 } /* Generic.Error */
.highlight .gh { color: #333333 } /* Generic.Heading */
.highlight .gi { color: #000000; background-color: #ddffdd } /* Generic.Inserted */
.highlight .go { color: #888888 } /* Generic.Output */
.highlight .gp { color: #555555 } /* Generic.Prompt */
.highlight .gs { font-weight: bold } /* Generic.Strong */
.highlight .gu { color: #666666 } /* Generic.Subheading */
.highlight .gt { color: #aa0000 } /* Generic.Traceback */
.highlight .kc { color: #008800; font-weight: bold } /* Keyword.Constant */
.highlight .kd { color: #008800; font-weight: bold } /* Keyword.Declaration */
.highlight .kn { color: #008800; font-weight: bold } /* Keyword.Namespace */
.highlight .kp { color: #008800 } /* Keyword.Pseudo */
.highlight .kr { color: #008800; font-weight: bold } /* Keyword.Reserved */
.highlight .kt { color: #888888; font-weight: bold } /* Keyword.Type */
.highlight .m { color: #0000DD; font-weight: bold } /* Literal.Number */
.highlight .s { color: #dd2200; background-color: #fff0f0 } /* Literal.String */
.highlight .na { color: #336699 } /* Name.Attribute */
.highlight .nb { color: #003388 } /* Name.Builtin */
.highlight .nc { color: #bb0066; font-weight: bold } /* Name.Class */
.highlight .no { color: #003366; font-weight: bold } /* Name.Constant */
.highlight .nd { color: #555555 } /* Name.Decorator */
.highlight .ne { color: #bb0066; font-weight: bold } /* Name.Exception */
.highlight .nf { color: #0066bb; font-weight: bold } /* Name.Function */
.highlight .nl { color: #336699; font-style: italic } /* Name.Label */
.highlight .nn { color: #bb0066; font-weight: bold } /* Name.Namespace */
.highlight .py { color: #336699; font-weight: bold } /* Name.Property */
.highlight .nt { color: #bb0066; font-weight: bold } /* Name.Tag */
.highlight .nv { color: #336699 } /* Name.Variable */
.highlight .ow { color: #008800 } /* Operator.Word */
.highlight .w { color: #bbbbbb } /* Text.Whitespace */
.highlight .mb { color: #0000DD; font-weight: bold } /* Literal.Number.Bin */
.highlight .mf { color: #0000DD; font-weight: bold } /* Literal.Number.Float */
.highlight .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */
.highlight .mi { color: #0000DD; font-weight: bold } /* Literal.Number.Integer */
.highlight .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */
.highlight .sa { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Affix */
.highlight .sb { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Backtick */
.highlight .sc { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Char */
.highlight .dl { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Delimiter */
.highlight .sd { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Doc */
.highlight .s2 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Double */
.highlight .se { color: #0044dd; background-color: #fff0f0 } /* Literal.String.Escape */
.highlight .sh { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Heredoc */
.highlight .si { color: #3333bb; background-color: #fff0f0 } /* Literal.String.Interpol */
.highlight .sx { color: #22bb22; background-color: #f0fff0 } /* Literal.String.Other */
.highlight .sr { color: #008800; background-color: #fff0ff } /* Literal.String.Regex */
.highlight .s1 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Single */
.highlight .ss { color: #aa6600; background-color: #fff0f0 } /* Literal.String.Symbol */
.highlight .bp { color: #003388 } /* Name.Builtin.Pseudo */
.highlight .fm { color: #0066bb; font-weight: bold } /* Name.Function.Magic */
.highlight .vc { color: #336699 } /* Name.Variable.Class */
.highlight .vg { color: #dd7700 } /* Name.Variable.Global */
.highlight .vi { color: #3333bb } /* Name.Variable.Instance */
.highlight .vm { color: #336699 } /* Name.Variable.Magic */
.highlight .il { color: #0000DD; font-weight: bold } /* Literal.Number.Integer.Long */
#
#
#            Nim's Runtime Library
#        (c) Copyright 2015 Nim Contributors
#
#    See the file "copying.txt", included in this
#    distribution, for details about the copyright.
#

## :Authors: Zahary Karadjov, Andreas Rumpf
##
## This module provides support for `memory mapped files`:idx:
## (Posix's `mmap`:idx:) on the different operating systems.
##
## It also provides some fast iterators over lines in text files (or
## other "line-like", variable length, delimited records).

when defined(windows):
  import winlean
elif defined(posix):
  import posix
else:
  {.error: "the memfiles module is not supported on your operating system!".}

import os

type
  MemFile* = object  ## represents a memory mapped file
    mem*: pointer    ## a pointer to the memory mapped file. The pointer
                     ## can be used directly to change the contents of the
                     ## file, if it was opened with write access.
    size*: int       ## size of the memory mapped file

    when defined(windows):
      fHandle: Handle
      mapHandle: Handle
      wasOpened: bool   ## only close if wasOpened
    else:
      handle: cint

{.deprecated: [TMemFile: MemFile].}

proc mapMem*(m: var MemFile, mode: FileMode = fmRead,
             mappedSize = -1, offset = 0): pointer =
  var readonly = mode == fmRead
  when defined(windows):
    result = mapViewOfFileEx(
      m.mapHandle,
      if readonly: FILE_MAP_READ else: FILE_MAP_WRITE,
      int32(offset shr 32),
      int32(offset and 0xffffffff),
      if mappedSize == -1: 0 else: mappedSize,
      nil)
    if result == nil:
      raiseOSError(osLastError())
  else:
    assert mappedSize > 0
    result = mmap(
      nil,
      mappedSize,
      if readonly: PROT_READ else: PROT_READ or PROT_WRITE,
      if readonly: (MAP_PRIVATE or MAP_POPULATE) else: (MAP_SHARED or MAP_POPULATE),
      m.handle, offset)
    if result == cast[pointer](MAP_FAILED):
      raiseOSError(osLastError())


proc unmapMem*(f: var MemFile, p: pointer, size: int) =
  ## unmaps the memory region ``(p, <p+size)`` of the mapped file `f`.
  ## All changes are written back to the file system, if `f` was opened
  ## with write access. ``size`` must be of exactly the size that was requested
  ## via ``mapMem``.
  when defined(windows):
    if unmapViewOfFile(p) == 0: raiseOSError(osLastError())
  else:
    if munmap(p, size) != 0: raiseOSError(osLastError())


proc open*(filename: string, mode: FileMode = fmRead,
           mappedSize = -1, offset = 0, newFileSize = -1): MemFile =
  ## opens a memory mapped file. If this fails, ``EOS`` is raised.
  ## `newFileSize` can only be set if the file does not exist and is opened
  ## with write access (e.g., with fmReadWrite). `mappedSize` and `offset`
  ## can be used to map only a slice of the file. Example:
  ##
  ## .. code-block:: nim
  ##   var
  ##     mm, mm_full, mm_half: MemFile
  ##
  ##   mm = memfiles.open("/tmp/test.mmap", mode = fmWrite, newFileSize = 1024)    # Create a new file
  ##   mm.close()
  ##
  ##   # Read the whole file, would fail if newFileSize was set
  ##   mm_full = memfiles.open("/tmp/test.mmap", mode = fmReadWrite, mappedSize = -1)
  ##
  ##   # Read the first 512 bytes
  ##   mm_half = memfiles.open("/tmp/test.mmap", mode = fmReadWrite, mappedSize = 512)

  # The file can be resized only when write mode is used:
  assert newFileSize == -1 or mode != fmRead
  var readonly = mode == fmRead

  template rollback =
    result.mem = nil
    result.size = 0

  when defined(windows):
    template fail(errCode: OSErrorCode, msg: expr) =
      rollback()
      if result.fHandle != 0: discard closeHandle(result.fHandle)
      if result.mapHandle != 0: discard closeHandle(result.mapHandle)
      raiseOSError(errCode)
      # return false
      #raise newException(EIO, msg)

    template callCreateFile(winApiProc, filename: expr): expr =
      winApiProc(
        filename,
        # GENERIC_ALL != (GENERIC_READ or GENERIC_WRITE)
        if readonly: GENERIC_READ else: GENERIC_READ or GENERIC_WRITE,
        FILE_SHARE_READ,
        nil,
        if newFileSize != -1: CREATE_ALWAYS else: OPEN_EXISTING,
        if readonly: FILE_ATTRIBUTE_READONLY else: FILE_ATTRIBUTE_TEMPORARY,
        0)

    when useWinUnicode:
      result.fHandle = callCreateFile(createFileW, newWideCString(filename))
    else:
      result.fHandle = callCreateFile(createFileA, filename)

    if result.fHandle == INVALID_HANDLE_VALUE:
      fail(osLastError(), "error opening file")

    if newFileSize != -1:
      var
        sizeHigh = int32(newFileSize shr 32)
        sizeLow  = int32(newFileSize and 0xffffffff)

      var status = setFilePointer(result.fHandle, sizeLow, addr(sizeHigh),
                                  FILE_BEGIN)
      let lastErr = osLastError()
      if (status == INVALID_SET_FILE_POINTER and lastErr.int32 != NO_ERROR) or
         (setEndOfFile(result.fHandle) == 0):
        fail(lastErr, "error setting file size")

    # since the strings are always 'nil', we simply always call
    # CreateFileMappingW which should be slightly faster anyway:
    result.mapHandle = createFileMappingW(
      result.fHandle, nil,
      if readonly: PAGE_READONLY else: PAGE_READWRITE,
      0, 0, nil)

    if result.mapHandle == 0:
      fail(osLastError(), "error creating mapping")

    result.mem = mapViewOfFileEx(
      result.mapHandle,
      if readonly: FILE_MAP_READ else: FILE_MAP_WRITE,
      int32(offset shr 32),
      int32(offset and 0xffffffff),
      if mappedSize == -1: 0 else: mappedSize,
      nil)

    if result.mem == nil:
      fail(osLastError(), "error mapping view")

    var hi, low: int32
    low = getFileSize(result.fHandle, addr(hi))
    if low == INVALID_FILE_SIZE:
      fail(osLastError(), "error getting file size")
    else:
      var fileSize = (int64(hi) shr 32) or low
      if mappedSize != -1: result.size = min(fileSize, mappedSize).int
      else: result.size = fileSize.int

    result.wasOpened = true

  else:
    template fail(errCode: OSErrorCode, msg: expr) =
      rollback()
      if result.handle != 0: discard close(result.handle)
      raiseOSError(errCode)

    var flags = if readonly: O_RDONLY else: O_RDWR

    if newFileSize != -1:
      flags = flags or O_CREAT or O_TRUNC
      var permissions_mode = S_IRUSR or S_IWUSR
      result.handle = open(filename, flags, permissions_mode)
    else:
      result.handle = open(filename, flags)

    if result.handle == -1:
      # XXX: errno is supposed to be set here
      # Is there an exception that wraps it?
      fail(osLastError(), "error opening file")

    if newFileSize != -1:
      if ftruncate(result.handle, newFileSize) == -1:
        fail(osLastError(), "error setting file size")

    if mappedSize != -1:
      result.size = mappedSize
    else:
      var stat: Stat
      if fstat(result.handle, stat) != -1:
        # XXX: Hmm, this could be unsafe
        # Why is mmap taking int anyway?
        result.size = int(stat.st_size)
      else:
        fail(osLastError(), "error getting file size")

    result.mem = mmap(
      nil,
      result.size,
      if readonly: PROT_READ else: PROT_READ or PROT_WRITE,
      if readonly: (MAP_PRIVATE or MAP_POPULATE) else: (MAP_SHARED or MAP_POPULATE),
      result.handle,
      offset)

    if result.mem == cast[pointer](MAP_FAILED):
      fail(osLastError(), "file mapping failed")

proc close*(f: var MemFile) =
  ## closes the memory mapped file `f`. All changes are written back to the
  ## file system, if `f` was opened with write access.

  var error = false
  var lastErr: OSErrorCode

  when defined(windows):
    if f.fHandle != INVALID_HANDLE_VALUE and f.wasOpened:
      error = unmapViewOfFile(f.mem) == 0
      lastErr = osLastError()
      error = (closeHandle(f.mapHandle) == 0) or error
      error = (closeHandle(f.fHandle) == 0) or error
  else:
    if f.handle != 0:
      error = munmap(f.mem, f.size) != 0
      lastErr = osLastError()
      error = (close(f.handle) != 0) or error

  f.size = 0
  f.mem = nil

  when defined(windows):
    f.fHandle = 0
    f.mapHandle = 0
    f.wasOpened = false
  else:
    f.handle = 0

  if error: raiseOSError(lastErr)

type MemSlice* = object  ## represent slice of a MemFile for iteration over delimited lines/records
  data*: pointer
  size*: int

proc c_memcpy(a, b: pointer, n: int) {.importc: "memcpy", header: "<string.h>".}

proc `$`*(ms: MemSlice): string {.inline.} =
  ## Return a Nim string built from a MemSlice.
  var buf = newString(ms.size)
  c_memcpy(addr(buf[0]), ms.data, ms.size)
  buf[ms.size] = '\0'
  result = buf

iterator memSlices*(mfile: MemFile, delim='\l', eat='\r'): MemSlice {.inline.} =
  ## Iterates over [optional `eat`] `delim`-delimited slices in MemFile `mfile`.
  ##
  ## Default parameters parse lines ending in either Unix(\\l) or Windows(\\r\\l)
  ## style on on a line-by-line basis.  I.e., not every line needs the same ending.
  ## Unlike readLine(File) & lines(File), archaic MacOS9 \\r-delimited lines
  ## are not supported as a third option for each line.  Such archaic MacOS9
  ## files can be handled by passing delim='\\r', eat='\\0', though.
  ##
  ## Delimiters are not part of the returned slice.  A final, unterminated line
  ## or record is returned just like any other.
  ##
  ## Non-default delimiters can be passed to allow iteration over other sorts
  ## of "line-like" variable length records.  Pass eat='\\0' to be strictly
  ## `delim`-delimited. (Eating an optional prefix equal to '\\0' is not
  ## supported.)
  ##
  ## This zero copy, memchr-limited interface is probably the fastest way to
  ## iterate over line-like records in a file.  However, returned (data,size)
  ## objects are not Nim strings, bounds checked Nim arrays, or even terminated
  ## C strings.  So, care is required to access the data (e.g., think C mem*
  ## functions, not str* functions).  Example:
  ##
  ## .. code-block:: nim
  ##   var count = 0
  ##   for slice in memSlices(memfiles.open("foo")):
  ##     if slice.size > 0 and cast[cstring](slice.data)[0] != '#':
  ##       inc(count)
  ##   echo count

  proc c_memchr(cstr: pointer, c: char, n: csize): pointer {.
       importc: "memchr", header: "<string.h>" .}
  proc `-!`(p, q: pointer): int {.inline.} = return cast[int](p) -% cast[int](q)
  var ms: MemSlice
  var ending: pointer
  ms.data = mfile.mem
  var remaining = mfile.size
  while remaining > 0:
    ending = c_memchr(ms.data, delim, remaining)
    if ending == nil:                               # unterminated final slice
      ms.size = remaining                           # Weird case..check eat?
      yield ms
      break
    ms.size = ending -! ms.data                     # delim is NOT included
    if eat != '\0' and ms.size > 0 and cast[cstring](ms.data)[ms.size - 1] == eat:
      dec(ms.size)                                  # trim pre-delim char
    yield ms
    ms.data = cast[pointer](cast[int](ending) +% 1)     # skip delim
    remaining = mfile.size - (ms.data -! mfile.mem)

iterator lines*(mfile: MemFile, buf: var TaintedString, delim='\l', eat='\r'): TaintedString {.inline.} =
  ## Replace contents of passed buffer with each new line, like
  ## `readLine(File) <system.html#readLine,File,TaintedString>`_.
  ## `delim`, `eat`, and delimiting logic is exactly as for
  ## `memSlices <#memSlices>`_, but Nim strings are returned.  Example:
  ##
  ## .. code-block:: nim
  ##   var buffer: TaintedString = ""
  ##   for line in lines(memfiles.open("foo"), buffer):
  ##     echo line

  for ms in memSlices(mfile, delim, eat):
    buf.setLen(ms.size)
    c_memcpy(addr(buf[0]), ms.data, ms.size)
    buf[ms.size] = '\0'
    yield buf

iterator lines*(mfile: MemFile, delim='\l', eat='\r'): TaintedString {.inline.} =
  ## Return each line in a file as a Nim string, like
  ## `lines(File) <system.html#lines.i,File>`_.
  ## `delim`, `eat`, and delimiting logic is exactly as for
  ## `memSlices <#memSlices>`_, but Nim strings are returned.  Example:
  ##
  ## .. code-block:: nim
  ##   for line in lines(memfiles.open("foo")):
  ##     echo line

  var buf = TaintedString(newStringOfCap(80))
  for line in lines(mfile, buf, delim, eat):
    yield buf