117 lines
4.6 KiB
C++
117 lines
4.6 KiB
C++
// Copyright 2014 The Crashpad Authors. All rights reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#ifndef CRASHPAD_SNAPSHOT_MEMORY_SNAPSHOT_H_
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#define CRASHPAD_SNAPSHOT_MEMORY_SNAPSHOT_H_
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#include <stdint.h>
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#include <sys/types.h>
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#include <memory>
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#include "util/numeric/checked_range.h"
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namespace crashpad {
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//! \brief An abstract interface to a snapshot representing a region of memory
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//! present in a snapshot process.
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class MemorySnapshot {
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public:
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//! \brief An interface that MemorySnapshot clients must implement in order to
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//! receive memory snapshot data.
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//!
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//! This callback-based model frees MemorySnapshot implementations from having
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//! to deal with memory region ownership problems. When a memory snapshot’s
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//! data is read, it will be passed to a delegate method.
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class Delegate {
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public:
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virtual ~Delegate() {}
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//! \brief Called by MemorySnapshot::Read() to provide data requested by a
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//! call to that method.
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//!
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//! \param[in] data A pointer to the data that was read. The callee does not
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//! take ownership of this data. This data is only valid for the
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//! duration of the call to this method. This parameter may be `nullptr`
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//! if \a size is `0`.
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//! \param[in] size The size of the data that was read.
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//!
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//! \return `true` on success, `false` on failure. MemoryDelegate::Read()
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//! will use this as its own return value.
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virtual bool MemorySnapshotDelegateRead(void* data, size_t size) = 0;
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};
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virtual ~MemorySnapshot() {}
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//! \brief The base address of the memory snapshot in the snapshot process’
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//! address space.
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virtual uint64_t Address() const = 0;
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//! \brief The size of the memory snapshot.
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virtual size_t Size() const = 0;
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//! \brief Calls Delegate::MemorySnapshotDelegateRead(), providing it with
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//! the memory snapshot’s data.
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//!
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//! Implementations do not necessarily read the memory snapshot data prior to
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//! this method being called. Memory snapshot data may be loaded lazily and
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//! may be discarded after being passed to the delegate. This provides clean
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//! memory management without burdening a snapshot implementation with the
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//! requirement that it track all memory region data simultaneously.
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//!
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//! \return `false` on failure, otherwise, the return value of
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//! Delegate::MemorySnapshotDelegateRead(), which should be `true` on
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//! success and `false` on failure.
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virtual bool Read(Delegate* delegate) const = 0;
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//! \brief Creates a new MemorySnapshot based on merging this one with \a
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//! other.
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//!
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//! The ranges described by the two snapshots must either overlap or abut, and
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//! must be of the same concrete type.
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//!
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//! \return A newly allocated MemorySnapshot representing the merged range, or
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//! `nullptr` with an error logged.
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virtual const MemorySnapshot* MergeWithOtherSnapshot(
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const MemorySnapshot* other) const = 0;
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};
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//! \brief Given two memory snapshots, checks if they're overlapping or
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//! abutting, and if so, returns the result of merging the two ranges.
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//!
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//! This function is useful to implement
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//! MemorySnapshot::MergeWithOtherSnapshot().
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//!
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//! \param[in] a The first range. Must have Size() > 0.
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//! \param[in] b The second range. Must have Size() > 0.
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//! \param[out] merged The resulting merged range. May be `nullptr` if only a
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//! characterization of the ranges is desired.
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//!
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//! \return `true` if the input ranges overlap or abut, with \a merged filled
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//! out, otherwise, `false` with an error logged if \a log is `true`.
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bool LoggingDetermineMergedRange(const MemorySnapshot* a,
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const MemorySnapshot* b,
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CheckedRange<uint64_t, size_t>* merged);
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//! \brief The same as LoggingDetermineMergedRange but with no errors logged.
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//!
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//! \sa LoggingDetermineMergedRange
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bool DetermineMergedRange(const MemorySnapshot* a,
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const MemorySnapshot* b,
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CheckedRange<uint64_t, size_t>* merged);
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} // namespace crashpad
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#endif // CRASHPAD_SNAPSHOT_MEMORY_SNAPSHOT_H_
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