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![Ryan Macnak](/assets/img/avatar_default.png)
In particular, avoid quadratic memory use in ZoneTextBuffer. Change-Id: I8d2ea77d35cd3c2c353ae557a2ee676ee8413653 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/95483 Reviewed-by: Vyacheslav Egorov <vegorov@google.com> Reviewed-by: Siva Annamalai <asiva@google.com> Commit-Queue: Ryan Macnak <rmacnak@google.com>
60 lines
1.7 KiB
C++
60 lines
1.7 KiB
C++
// Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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#include "vm/zone_text_buffer.h"
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#include "platform/assert.h"
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#include "platform/globals.h"
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#include "platform/utils.h"
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#include "vm/os.h"
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#include "vm/zone.h"
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namespace dart {
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ZoneTextBuffer::ZoneTextBuffer(Zone* zone, intptr_t initial_capacity)
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: zone_(zone), buffer_(NULL), length_(0), capacity_(0) {
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ASSERT(initial_capacity > 0);
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buffer_ = reinterpret_cast<char*>(zone->Alloc<char>(initial_capacity));
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capacity_ = initial_capacity;
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buffer_[length_] = '\0';
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}
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intptr_t ZoneTextBuffer::Printf(const char* format, ...) {
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va_list args;
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va_start(args, format);
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intptr_t remaining = capacity_ - length_;
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ASSERT(remaining >= 0);
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intptr_t len = Utils::VSNPrint(buffer_ + length_, remaining, format, args);
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va_end(args);
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if (len >= remaining) {
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EnsureCapacity(len);
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remaining = capacity_ - length_;
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ASSERT(remaining > len);
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va_list args2;
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va_start(args2, format);
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intptr_t len2 =
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Utils::VSNPrint(buffer_ + length_, remaining, format, args2);
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va_end(args2);
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ASSERT(len == len2);
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}
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length_ += len;
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buffer_[length_] = '\0';
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return len;
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}
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void ZoneTextBuffer::AddString(const char* s) {
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Printf("%s", s);
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}
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void ZoneTextBuffer::EnsureCapacity(intptr_t len) {
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intptr_t remaining = capacity_ - length_;
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if (remaining <= len) {
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intptr_t new_capacity = capacity_ + Utils::Maximum(capacity_, len);
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buffer_ = zone_->Realloc<char>(buffer_, capacity_, new_capacity);
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capacity_ = new_capacity;
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}
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}
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} // namespace dart
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