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mirror of synced 2024-11-28 09:30:51 +01:00
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fix: Highest / Lowest entropy block address being wrong

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This commit is contained in:
WerWolv 2023-08-06 01:51:01 +02:00
parent 55e6761bf1
commit f2cfc70eca
1 changed files with 23 additions and 17 deletions
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40
plugins/builtin/include/content/helpers/diagrams.hpp
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@ -310,7 +310,7 @@ namespace hex {
ImGuiCond_Always);
// Draw the plot
ImPlot::PlotLine("##ChunkBasedAnalysisLine", this->m_xBlockEntropy.data(), this->m_yBlockEntropy.data(), this->m_xBlockEntropy.size());
ImPlot::PlotLine("##ChunkBasedAnalysisLine", this->m_xBlockEntropy.data(), this->m_yBlockEntropySampled.data(), this->m_xBlockEntropy.size());
// The parameter updateHandle is used when using the pattern language since we don't have a provider
// but just a set of bytes we won't be able to use the drag bar correctly.
@ -431,15 +431,21 @@ namespace hex {
double calculateEntropy(std::array<ImU64, 256> &valueCounts, size_t blockSize) {
double entropy = 0;
u8 processedValueCount = 0;
for (auto count : valueCounts) {
if (count == 0) [[unlikely]]
continue;
processedValueCount += 1;
double probability = static_cast<double>(count) / blockSize;
entropy += probability * std::log2(probability);
}
if (processedValueCount == 1)
return 0.0;
return std::min<double>(1.0, (-entropy) / 8); // log2(256) = 8
}
@ -456,7 +462,7 @@ namespace hex {
u64 address = 0x00;
if (!this->m_yBlockEntropy.empty())
address = (std::max_element(this->m_yBlockEntropy.begin(), this->m_yBlockEntropy.end()) - this->m_yBlockEntropy.begin()) * this->m_blockSize;
return address;
return this->m_startAddress + address;
}
// Return the highest entropy value among all of the blocks
@ -472,12 +478,12 @@ namespace hex {
u64 address = 0x00;
if (this->m_yBlockEntropy.size() > 1)
address = (std::min_element(this->m_yBlockEntropy.begin(), this->m_yBlockEntropy.end() - 1) - this->m_yBlockEntropy.begin()) * this->m_blockSize;
return address;
return this->m_startAddress + address;
}
// Return the number of blocks that have been processed
u64 getSize() {
return this->m_yBlockEntropy.size();
return this->m_yBlockEntropySampled.size();
}
// Return the size of the chunk used for this analysis
@ -519,15 +525,15 @@ namespace hex {
void processFinalize() {
// Only save at most m_sampleSize elements of the result
this->m_yBlockEntropy = sampleData(this->m_yBlockEntropy, std::min<size_t>(this->m_blockCount + 1, this->m_sampleSize));
this->m_yBlockEntropySampled = sampleData(this->m_yBlockEntropy, std::min<size_t>(this->m_blockCount + 1, this->m_sampleSize));
if (!this->m_yBlockEntropy.empty())
this->m_yBlockEntropy.push_back(this->m_yBlockEntropy.back());
if (!this->m_yBlockEntropySampled.empty())
this->m_yBlockEntropySampled.push_back(this->m_yBlockEntropySampled.back());
double stride = std::max(1.0, double(
double(std::ceil((this->m_endAddress - this->m_startAddress)) / this->m_blockSize) / this->m_yBlockEntropy.size()));
double(std::ceil((this->m_endAddress - this->m_startAddress)) / this->m_blockSize) / this->m_yBlockEntropySampled.size()));
this->m_blockCount = this->m_yBlockEntropy.size() - 1;
this->m_blockCount = this->m_yBlockEntropySampled.size() - 1;
// The m_xBlockEntropy attribute is used to specify the position of entropy values
// in the plot when the Y axis doesn't start at 0
@ -569,7 +575,7 @@ namespace hex {
// Variable to hold the result of the chunk based
// entropy analysis
std::vector<double> m_xBlockEntropy;
std::vector<double> m_yBlockEntropy;
std::vector<double> m_yBlockEntropy, m_yBlockEntropySampled;
// Sampling size, number of elements displayed in the plot,
// avoid showing to many data because it decreased the frame rate
@ -698,7 +704,7 @@ namespace hex {
};
for (u32 i = 0; i < Names.size(); i++) {
ImPlot::PlotLine(Names[i], this->m_xBlockTypeDistributions.data(), this->m_yBlockTypeDistributions[i].data(), this->m_xBlockTypeDistributions.size());
ImPlot::PlotLine(Names[i], this->m_xBlockTypeDistributions.data(), this->m_yBlockTypeDistributionsSampled[i].data(), this->m_xBlockTypeDistributions.size());
}
// The parameter updateHandle is used when using the pattern language since we don't have a provider
@ -896,14 +902,14 @@ namespace hex {
void processFinalize() {
// Only save at most m_sampleSize elements of the result
for (size_t i = 0; i < this->m_yBlockTypeDistributions.size(); ++i) {
this->m_yBlockTypeDistributions[i] = sampleData(this->m_yBlockTypeDistributions[i], std::min<size_t>(this->m_blockCount + 1, this->m_sampleSize));
this->m_yBlockTypeDistributionsSampled[i] = sampleData(this->m_yBlockTypeDistributions[i], std::min<size_t>(this->m_blockCount + 1, this->m_sampleSize));
if (!this->m_yBlockTypeDistributions[i].empty())
this->m_yBlockTypeDistributions[i].push_back(this->m_yBlockTypeDistributions[i].back());
if (!this->m_yBlockTypeDistributionsSampled[i].empty())
this->m_yBlockTypeDistributionsSampled[i].push_back(this->m_yBlockTypeDistributionsSampled[i].back());
}
double stride = std::max(1.0, double(this->m_blockCount) / this->m_yBlockTypeDistributions[0].size());
this->m_blockCount = this->m_yBlockTypeDistributions[0].size() - 1;
double stride = std::max(1.0, double(this->m_blockCount) / this->m_yBlockTypeDistributionsSampled[0].size());
this->m_blockCount = this->m_yBlockTypeDistributionsSampled[0].size() - 1;
// The m_xBlockTypeDistributions attribute is used to specify the position of entropy
// values in the plot when the Y axis doesn't start at 0
@ -948,7 +954,7 @@ namespace hex {
// the values in the plot when the Y axis doesn't start at 0
std::vector<float> m_xBlockTypeDistributions;
// Hold the result of the byte distribution analysis
std::array<std::vector<float>, 12> m_yBlockTypeDistributions;
std::array<std::vector<float>, 12> m_yBlockTypeDistributions, m_yBlockTypeDistributionsSampled;
std::atomic<bool> m_processing = false;
};
}