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// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "ui/display/manager/util/display_manager_test_util.h"
#include <stdint.h>
#include "base/check_op.h"
#include "ui/display/display_features.h"
#include "ui/display/util/display_util.h"
namespace display {
namespace {
// Use larger than max int to catch overflow early.
constexpr int64_t kSynthesizedDisplayIdStart = 2200000000LL;
int64_t next_synthesized_display_id = kSynthesizedDisplayIdStart;
uint8_t edid_device_index = 0;
uint8_t edid_display_index = 0;
} // namespace
void ResetDisplayIdForTest() {
next_synthesized_display_id = kSynthesizedDisplayIdStart;
edid_device_index = 0;
edid_display_index = 0;
}
int64_t GetASynthesizedDisplayId() {
const int64_t id = next_synthesized_display_id;
next_synthesized_display_id =
features::IsEdidBasedDisplayIdsEnabled()
? next_synthesized_display_id += 0x100
: SynthesizeDisplayIdFromSeed(next_synthesized_display_id);
return id;
}
int64_t SynthesizeDisplayIdFromSeed(int64_t id) {
// Connector index is stored in the first 8 bits for port-base display IDs.
int next_output_index = id & 0xFF;
next_output_index++;
DCHECK_GT(0x100, next_output_index);
const int64_t base = static_cast<int64_t>(~static_cast<uint64_t>(0xFF) & id);
if (id == kSynthesizedDisplayIdStart) {
return id + 0x100 + next_output_index;
}
return base + next_output_index;
}
int64_t GetNextSynthesizedEdidDisplayConnectorIndex() {
if (edid_display_index == 255) {
edid_display_index = 0;
edid_device_index++;
} else {
edid_display_index++;
}
// Synthesized IDs are limited to 256^2 unique IDs.
DCHECK_LT(edid_device_index, 255)
<< "Connector index exceeded 65536. Cannot "
"synthesize any more unique display IDs.";
return ConnectorIndex16(edid_device_index, edid_display_index);
}
int64_t ProduceAlternativeSchemeIdForId(int64_t id) {
DCHECK_GT(id, 0);
int magnitude = 1;
int64_t id_copy = id;
do {
magnitude *= 10;
id_copy /= 10;
} while (id_copy / 10);
const int64_t new_id = id - magnitude;
return new_id > 0 ? new_id : id + magnitude;
}
} // namespace display
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