Add FileReaderInterface. Move StringFileWriter to StringFile and

util/file/string_file_writer.cc

Index: util/file/string_file_writer.cc
diff --git a/util/file/string_file_writer.cc b/util/file/string_file_writer.cc
deleted file mode 100644
index e2669b3264c8a011cc127e4e8eb0a412106fca28..0000000000000000000000000000000000000000
--- a/util/file/string_file_writer.cc
+++ /dev/null
@@ -1,138 +0,0 @@
-// Copyright 2014 The Crashpad Authors. All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "util/file/string_file_writer.h"
-
-#include <string.h>
-
-#include "base/logging.h"
-#include "base/numerics/safe_math.h"
-#include "util/numeric/safe_assignment.h"
-
-namespace crashpad {
-
-StringFileWriter::StringFileWriter() : string_(), offset_(0) {
-}
-
-StringFileWriter::~StringFileWriter() {
-}
-
-void StringFileWriter::Reset() {
-  string_.clear();
-  offset_ = 0;
-}
-
-bool StringFileWriter::Write(const void* data, size_t size) {
-  DCHECK(offset_.IsValid());
-
-  const size_t offset = offset_.ValueOrDie();
-  if (offset > string_.size()) {
-    string_.resize(offset);
-  }
-
-  base::CheckedNumeric<ssize_t> new_offset = offset_;
-  new_offset += size;
-  if (!new_offset.IsValid()) {
-    LOG(ERROR) << "Write(): file too large";
-    return false;
-  }
-
-  string_.replace(offset, size, reinterpret_cast<const char*>(data), size);
-  offset_ = new_offset;
-
-  return true;
-}
-
-bool StringFileWriter::WriteIoVec(std::vector<WritableIoVec>* iovecs) {
-  DCHECK(offset_.IsValid());
-
-  if (iovecs->empty()) {
-    LOG(ERROR) << "WriteIoVec(): no iovecs";
-    return false;
-  }
-
-  // Avoid writing anything at all if it would cause an overflow.
-  base::CheckedNumeric<ssize_t> new_offset = offset_;
-  for (const WritableIoVec& iov : *iovecs) {
-    new_offset += iov.iov_len;
-    if (!new_offset.IsValid()) {
-      LOG(ERROR) << "WriteIoVec(): file too large";
-      return false;
-    }
-  }
-
-  for (const WritableIoVec& iov : *iovecs) {
-    if (!Write(iov.iov_base, iov.iov_len)) {
-      return false;
-    }
-  }
-
-#ifndef NDEBUG
-  // The interface says that |iovecs| is not sacred, so scramble it to make sure
-  // that nobody depends on it.
-  memset(&(*iovecs)[0], 0xa5, sizeof((*iovecs)[0]) * iovecs->size());
-#endif
-
-  return true;
-}
-
-FileOffset StringFileWriter::Seek(FileOffset offset, int whence) {
-  DCHECK(offset_.IsValid());
-
-  size_t base_offset;
-
-  switch (whence) {
-    case SEEK_SET:
-      base_offset = 0;
-      break;
-
-    case SEEK_CUR:
-      base_offset = offset_.ValueOrDie();
-      break;
-
-    case SEEK_END:
-      base_offset = string_.size();
-      break;
-
-    default:
-      LOG(ERROR) << "Seek(): invalid whence " << whence;
-      return -1;
-  }
-
-  FileOffset base_offset_fileoffset;
-  if (!AssignIfInRange(&base_offset_fileoffset, base_offset)) {
-    LOG(ERROR) << "Seek(): base_offset " << base_offset
-               << " invalid for FileOffset";
-    return -1;
-  }
-  base::CheckedNumeric<FileOffset> new_offset(base_offset_fileoffset);
-  new_offset += offset;
-  if (!new_offset.IsValid()) {
-    LOG(ERROR) << "Seek(): new_offset invalid";
-    return -1;
-  }
-  FileOffset new_offset_fileoffset = new_offset.ValueOrDie();
-  size_t new_offset_sizet;
-  if (!AssignIfInRange(&new_offset_sizet, new_offset_fileoffset)) {
-    LOG(ERROR) << "Seek(): new_offset " << new_offset_fileoffset
-               << " invalid for size_t";
-    return -1;
-  }
-
-  offset_ = new_offset_sizet;
-
-  return offset_.ValueOrDie();
-}
-
-}  // namespace crashpad