gecko-dev/xpcom/base/nsINIParser.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/. */

// Moz headers (alphabetical)
#include "nsCRTGlue.h"
#include "nsError.h"
#include "nsIFile.h"
#include "nsINIParser.h"
#include "mozilla/ResultExtensions.h"
#include "mozilla/URLPreloader.h"

using namespace mozilla;

nsresult
nsINIParser::Init(nsIFile* aFile)
{
  nsCString result;
  MOZ_TRY_VAR(result, URLPreloader::ReadFile(aFile));

  return InitFromString(result);
}

static const char kNL[] = "\r\n";
static const char kEquals[] = "=";
static const char kWhitespace[] = " \t";
static const char kRBracket[] = "]";

nsresult
nsINIParser::InitFromString(const nsCString& aStr)
{
  nsCString fileContents;
  char* buffer;

  if (StringHead(aStr, 3) == "\xEF\xBB\xBF") {
    // Someone set us up the Utf-8 BOM
    // This case is easy, since we assume that BOM-less
    // files are Utf-8 anyway.  Just skip the BOM and process as usual.
    fileContents.Append(aStr);
    buffer = fileContents.BeginWriting() + 3;
  } else {
    if (StringHead(aStr, 2) == "\xFF\xFE") {
      // Someone set us up the Utf-16LE BOM
      nsDependentSubstring str(reinterpret_cast<const char16_t*>(aStr.get()),
                               aStr.Length() / 2);

      AppendUTF16toUTF8(Substring(str, 1), fileContents);
    } else {
      fileContents.Append(aStr);
    }

    buffer = fileContents.BeginWriting();
  }

  char* currSection = nullptr;

  // outer loop tokenizes into lines
  while (char* token = NS_strtok(kNL, &buffer)) {
    if (token[0] == '#' || token[0] == ';') { // it's a comment
      continue;
    }

    token = (char*)NS_strspnp(kWhitespace, token);
    if (!*token) { // empty line
      continue;
    }

    if (token[0] == '[') { // section header!
      ++token;
      currSection = token;

      char* rb = NS_strtok(kRBracket, &token);
      if (!rb || NS_strtok(kWhitespace, &token)) {
        // there's either an unclosed [Section or a [Section]Moretext!
        // we could frankly decide that this INI file is malformed right
        // here and stop, but we won't... keep going, looking for
        // a well-formed [section] to continue working with
        currSection = nullptr;
      }

      continue;
    }

    if (!currSection) {
      // If we haven't found a section header (or we found a malformed
      // section header), don't bother parsing this line.
      continue;
    }

    char* key = token;
    char* e = NS_strtok(kEquals, &token);
    if (!e || !token) {
      continue;
    }

    SetString(currSection, key, token);
  }

  return NS_OK;
}

bool
nsINIParser::IsValidSection(const char* aSection)
{
  if (aSection[0] == '\0') {
    return false;
  }

  const char* found = strpbrk(aSection, "\r\n[]");
  return found == nullptr;
}

bool
nsINIParser::IsValidKey(const char* aKey)
{
  if (aKey[0] == '\0') {
    return false;
  }

  const char* found = strpbrk(aKey, "\r\n=");
  return found == nullptr;
}

bool
nsINIParser::IsValidValue(const char* aValue)
{
  const char* found = strpbrk(aValue, "\r\n");
  return found == nullptr;
}

nsresult
nsINIParser::GetString(const char* aSection, const char* aKey,
                       nsACString& aResult)
{
  if (!IsValidSection(aSection) || !IsValidKey(aKey)) {
    return NS_ERROR_INVALID_ARG;
  }

  INIValue* val;
  mSections.Get(aSection, &val);

  while (val) {
    if (strcmp(val->key, aKey) == 0) {
      aResult.Assign(val->value);
      return NS_OK;
    }

    val = val->next.get();
  }

  return NS_ERROR_FAILURE;
}

nsresult
nsINIParser::GetString(const char* aSection, const char* aKey,
                       char* aResult, uint32_t aResultLen)
{
  if (!IsValidSection(aSection) || !IsValidKey(aKey)) {
    return NS_ERROR_INVALID_ARG;
  }

  INIValue* val;
  mSections.Get(aSection, &val);

  while (val) {
    if (strcmp(val->key, aKey) == 0) {
      strncpy(aResult, val->value, aResultLen);
      aResult[aResultLen - 1] = '\0';
      if (strlen(val->value) >= aResultLen) {
        return NS_ERROR_LOSS_OF_SIGNIFICANT_DATA;
      }

      return NS_OK;
    }

    val = val->next.get();
  }

  return NS_ERROR_FAILURE;
}

nsresult
nsINIParser::GetSections(INISectionCallback aCB, void* aClosure)
{
  for (auto iter = mSections.Iter(); !iter.Done(); iter.Next()) {
    if (!aCB(iter.Key(), aClosure)) {
      break;
    }
  }
  return NS_OK;
}

nsresult
nsINIParser::GetStrings(const char* aSection,
                        INIStringCallback aCB, void* aClosure)
{
  if (!IsValidSection(aSection)) {
    return NS_ERROR_INVALID_ARG;
  }

  INIValue* val;

  for (mSections.Get(aSection, &val);
       val;
       val = val->next.get()) {

    if (!aCB(val->key, val->value, aClosure)) {
      return NS_OK;
    }
  }

  return NS_OK;
}

nsresult
nsINIParser::SetString(const char* aSection, const char* aKey, const char* aValue)
{
  if (!IsValidSection(aSection) || !IsValidKey(aKey) || !IsValidValue(aValue)) {
    return NS_ERROR_INVALID_ARG;
  }

  INIValue* v;
  if (!mSections.Get(aSection, &v)) {
    v = new INIValue(aKey, aValue);

    mSections.Put(aSection, v);
    return NS_OK;
  }

  // Check whether this key has already been specified; overwrite
  // if so, or append if not.
  while (v) {
    if (!strcmp(aKey, v->key)) {
      v->SetValue(aValue);
      break;
    }
    if (!v->next) {
      v->next = MakeUnique<INIValue>(aKey, aValue);
      break;
    }
    v = v->next.get();
  }
  NS_ASSERTION(v, "v should never be null coming out of this loop");

  return NS_OK;
}

nsresult
nsINIParser::DeleteString(const char* aSection, const char* aKey)
{
  if (!IsValidSection(aSection) || !IsValidKey(aKey)) {
    return NS_ERROR_INVALID_ARG;
  }

  INIValue* val;
  if (!mSections.Get(aSection, &val)) {
    return NS_ERROR_FAILURE;
  }

  // Special case the first result
  if (strcmp(val->key, aKey) == 0) {
    if (!val->next) {
      mSections.Remove(aSection);
    } else {
      mSections.Put(aSection, val->next.release());
      delete val;
    }
    return NS_OK;
  }

  while (val->next) {
    if (strcmp(val->next->key, aKey) == 0) {
      val->next = std::move(val->next->next);

      return NS_OK;
    }

    val = val->next.get();
  }

  return NS_ERROR_FAILURE;
}

nsresult
nsINIParser::DeleteSection(const char* aSection)
{
  if (!IsValidSection(aSection)) {
    return NS_ERROR_INVALID_ARG;
  }

  if (!mSections.Remove(aSection)) {
    return NS_ERROR_FAILURE;
  }
  return NS_OK;
}

nsresult
nsINIParser::WriteToFile(nsIFile *aFile) {
  nsCString buffer;

  for (auto iter = mSections.Iter(); !iter.Done(); iter.Next()) {
    buffer.AppendPrintf("[%s]\n", iter.Key());
    INIValue* val = iter.Data();
    while (val) {
      buffer.AppendPrintf("%s=%s\n", val->key, val->value);
      val = val->next.get();
    }
    buffer.AppendLiteral("\n");
  }

  FILE* writeFile;
  nsresult rv = aFile->OpenANSIFileDesc("w", &writeFile);
  NS_ENSURE_SUCCESS(rv, rv);

  unsigned int length = buffer.Length();

  if (fwrite(buffer.get(), sizeof(char), length, writeFile) != length) {
      fclose(writeFile);
      return NS_ERROR_UNEXPECTED;
  }

  fclose(writeFile);
  return NS_OK;
}