gecko-dev/xpcom/io/nsLocalFileCommon.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsIServiceManager.h"

#include "nsLocalFile.h"  // includes platform-specific headers

#include "nsString.h"
#include "nsCOMPtr.h"
#include "nsReadableUtils.h"
#include "nsPrintfCString.h"
#include "nsCRT.h"
#include "nsNativeCharsetUtils.h"
#include "nsUTF8Utils.h"
#include "nsArray.h"

#ifdef XP_WIN
#  include <string.h>
#endif

#if !defined(MOZ_WIDGET_COCOA) && !defined(XP_WIN)
NS_IMETHODIMP
nsLocalFile::InitWithFile(nsIFile* aFile) {
  if (NS_WARN_IF(!aFile)) {
    return NS_ERROR_INVALID_ARG;
  }

  nsAutoCString path;
  aFile->GetNativePath(path);
  if (path.IsEmpty()) {
    return NS_ERROR_INVALID_ARG;
  }
  return InitWithNativePath(path);
}
#endif

#define kMaxFilenameLength 255
#define kMaxExtensionLength 100
#define kMaxSequenceNumberLength 5  // "-9999"
// requirement: kMaxExtensionLength <
//                kMaxFilenameLength - kMaxSequenceNumberLength

NS_IMETHODIMP
nsLocalFile::CreateUnique(uint32_t aType, uint32_t aAttributes) {
  nsresult rv;
  bool longName;

#ifdef XP_WIN
  nsAutoString pathName, leafName, rootName, suffix;
  rv = GetPath(pathName);
#else
  nsAutoCString pathName, leafName, rootName, suffix;
  rv = GetNativePath(pathName);
#endif
  if (NS_FAILED(rv)) {
    return rv;
  }

  auto FailedBecauseExists = [&](nsresult aRv) {
    if (aRv == NS_ERROR_FILE_ACCESS_DENIED) {
      bool exists;
      return NS_SUCCEEDED(Exists(&exists)) && exists;
    }
    return aRv == NS_ERROR_FILE_ALREADY_EXISTS;
  };

  longName =
      (pathName.Length() + kMaxSequenceNumberLength > kMaxFilenameLength);
  if (!longName) {
    rv = Create(aType, aAttributes);
    if (!FailedBecauseExists(rv)) {
      return rv;
    }
  }

#ifdef XP_WIN
  rv = GetLeafName(leafName);
  if (NS_FAILED(rv)) {
    return rv;
  }

  const int32_t lastDot = leafName.RFindChar(char16_t('.'));
#else
  rv = GetNativeLeafName(leafName);
  if (NS_FAILED(rv)) {
    return rv;
  }

  const int32_t lastDot = leafName.RFindChar('.');
#endif

  if (lastDot == kNotFound) {
    rootName = leafName;
  } else {
    suffix = Substring(leafName, lastDot);       // include '.'
    rootName = Substring(leafName, 0, lastDot);  // strip suffix and dot
  }

  if (longName) {
    int32_t maxRootLength =
        (kMaxFilenameLength - (pathName.Length() - leafName.Length()) -
         suffix.Length() - kMaxSequenceNumberLength);

    // We cannot create an item inside a directory whose name is too long.
    // Also, ensure that at least one character remains after we truncate
    // the root name, as we don't want to end up with an empty leaf name.
    if (maxRootLength < 2) {
      return NS_ERROR_FILE_UNRECOGNIZED_PATH;
    }

#ifdef XP_WIN
    // ensure that we don't cut the name in mid-UTF16-character
    rootName.SetLength(NS_IS_LOW_SURROGATE(rootName[maxRootLength])
                           ? maxRootLength - 1
                           : maxRootLength);
    SetLeafName(rootName + suffix);
#else
    if (NS_IsNativeUTF8()) {
      // ensure that we don't cut the name in mid-UTF8-character
      // (assume the name is valid UTF8 to begin with)
      while (UTF8traits::isInSeq(rootName[maxRootLength])) {
        --maxRootLength;
      }

      // Another check to avoid ending up with an empty leaf name.
      if (maxRootLength == 0 && suffix.IsEmpty()) {
        return NS_ERROR_FILE_UNRECOGNIZED_PATH;
      }
    }

    rootName.SetLength(maxRootLength);
    SetNativeLeafName(rootName + suffix);
#endif
    nsresult rvCreate = Create(aType, aAttributes);
    if (!FailedBecauseExists(rvCreate)) {
      return rvCreate;
    }
  }

  for (int indx = 1; indx < 10000; ++indx) {
    // start with "Picture-1.jpg" after "Picture.jpg" exists
#ifdef XP_WIN
    SetLeafName(rootName +
                NS_ConvertASCIItoUTF16(nsPrintfCString("-%d", indx)) + suffix);
#else
    SetNativeLeafName(rootName + nsPrintfCString("-%d", indx) + suffix);
#endif
    rv = Create(aType, aAttributes);
    if (NS_SUCCEEDED(rv) || !FailedBecauseExists(rv)) {
      return rv;
    }
  }

  // The disk is full, sort of
  return NS_ERROR_FILE_TOO_BIG;
}

#if defined(XP_WIN)
static const char16_t kPathSeparatorChar = '\\';
#elif defined(XP_UNIX)
static const char16_t kPathSeparatorChar = '/';
#else
#  error Need to define file path separator for your platform
#endif

static void SplitPath(char16_t* aPath, nsTArray<char16_t*>& aNodeArray) {
  if (*aPath == 0) {
    return;
  }

  if (*aPath == kPathSeparatorChar) {
    aPath++;
  }
  aNodeArray.AppendElement(aPath);

  for (char16_t* cp = aPath; *cp != 0; ++cp) {
    if (*cp == kPathSeparatorChar) {
      *cp++ = 0;
      if (*cp == 0) {
        break;
      }
      aNodeArray.AppendElement(cp);
    }
  }
}

NS_IMETHODIMP
nsLocalFile::GetRelativeDescriptor(nsIFile* aFromFile, nsACString& aResult) {
  if (NS_WARN_IF(!aFromFile)) {
    return NS_ERROR_INVALID_ARG;
  }

  //
  // aResult will be UTF-8 encoded
  //

  nsresult rv;
  aResult.Truncate(0);

  nsAutoString thisPath, fromPath;
  AutoTArray<char16_t*, 32> thisNodes;
  AutoTArray<char16_t*, 32> fromNodes;

  rv = GetPath(thisPath);
  if (NS_FAILED(rv)) {
    return rv;
  }
  rv = aFromFile->GetPath(fromPath);
  if (NS_FAILED(rv)) {
    return rv;
  }

  // get raw pointer to mutable string buffer
  char16_t* thisPathPtr = thisPath.BeginWriting();
  char16_t* fromPathPtr = fromPath.BeginWriting();

  SplitPath(thisPathPtr, thisNodes);
  SplitPath(fromPathPtr, fromNodes);

  size_t nodeIndex;
  for (nodeIndex = 0;
       nodeIndex < thisNodes.Length() && nodeIndex < fromNodes.Length();
       ++nodeIndex) {
#ifdef XP_WIN
    if (_wcsicmp(char16ptr_t(thisNodes[nodeIndex]),
                 char16ptr_t(fromNodes[nodeIndex]))) {
      break;
    }
#else
    if (nsCRT::strcmp(thisNodes[nodeIndex], fromNodes[nodeIndex])) {
      break;
    }
#endif
  }

  size_t branchIndex = nodeIndex;
  for (nodeIndex = branchIndex; nodeIndex < fromNodes.Length(); ++nodeIndex) {
    aResult.AppendLiteral("../");
  }
  for (nodeIndex = branchIndex; nodeIndex < thisNodes.Length(); ++nodeIndex) {
    NS_ConvertUTF16toUTF8 nodeStr(thisNodes[nodeIndex]);
    aResult.Append(nodeStr);
    if (nodeIndex + 1 < thisNodes.Length()) {
      aResult.Append('/');
    }
  }

  return NS_OK;
}

NS_IMETHODIMP
nsLocalFile::SetRelativeDescriptor(nsIFile* aFromFile,
                                   const nsACString& aRelativeDesc) {
  NS_NAMED_LITERAL_CSTRING(kParentDirStr, "../");

  nsCOMPtr<nsIFile> targetFile;
  nsresult rv = aFromFile->Clone(getter_AddRefs(targetFile));
  if (NS_FAILED(rv)) {
    return rv;
  }

  //
  // aRelativeDesc is UTF-8 encoded
  //

  nsCString::const_iterator strBegin, strEnd;
  aRelativeDesc.BeginReading(strBegin);
  aRelativeDesc.EndReading(strEnd);

  nsCString::const_iterator nodeBegin(strBegin), nodeEnd(strEnd);
  nsCString::const_iterator pos(strBegin);

  nsCOMPtr<nsIFile> parentDir;
  while (FindInReadable(kParentDirStr, nodeBegin, nodeEnd)) {
    rv = targetFile->GetParent(getter_AddRefs(parentDir));
    if (NS_FAILED(rv)) {
      return rv;
    }
    if (!parentDir) {
      return NS_ERROR_FILE_UNRECOGNIZED_PATH;
    }
    targetFile = parentDir;

    nodeBegin = nodeEnd;
    pos = nodeEnd;
    nodeEnd = strEnd;
  }

  nodeBegin = nodeEnd = pos;
  while (nodeEnd != strEnd) {
    FindCharInReadable('/', nodeEnd, strEnd);
    targetFile->Append(NS_ConvertUTF8toUTF16(Substring(nodeBegin, nodeEnd)));
    if (nodeEnd != strEnd) {  // If there's more left in the string, inc over
                              // the '/' nodeEnd is on.
      ++nodeEnd;
    }
    nodeBegin = nodeEnd;
  }

  return InitWithFile(targetFile);
}

NS_IMETHODIMP
nsLocalFile::GetRelativePath(nsIFile* aFromFile, nsACString& aResult) {
  return GetRelativeDescriptor(aFromFile, aResult);
}

NS_IMETHODIMP
nsLocalFile::SetRelativePath(nsIFile* aFromFile,
                             const nsACString& aRelativePath) {
  return SetRelativeDescriptor(aFromFile, aRelativePath);
}