private void ExtractPage(PageOptions options, JsonMapNode root)
{
Stopwatch w = Stopwatch.StartNew();
Console.WriteLine($"Extracting {options.Count:n0} results from index {options.Index:n0}\r\n from \"{options.InputFilePath}\"\r\n into \"{options.OutputFilePath}\"...");
JsonMapNode runs, run, results;
// Get 'runs' node from map. If log was too small, page using the object model
if (root == null ||
root.Nodes == null ||
root.Nodes.TryGetValue("runs", out runs) == false)
{
PageViaOm(options);
return;
}
// Verify RunIndex in range
if (options.RunIndex >= runs.Count)
{
throw new ArgumentOutOfRangeException($"Page requested for RunIndex {options.RunIndex}, but Log had only {runs.Count} runs.");
}
// Get 'results' from map. If log was too small, page using the object model
if (!runs.Nodes.TryGetValue(options.RunIndex.ToString(), out run) ||
run.Nodes == null ||
run.Nodes.TryGetValue("results", out results) == false ||
results.ArrayStarts == null)
{
// Log too small; convert via OM
PageViaOm(options);
return;
}
if (options.Index + options.Count > results.Count)
{
throw new ArgumentOutOfRangeException($"Page requested from Result {options.Index} to {options.Index + options.Count}, but Run has only {results.Count} results.");
}
Console.WriteLine($"Run {options.RunIndex} in \"{options.InputFilePath}\" has {results.Count:n0} results.");
Func <Stream> inputStreamProvider = () => _fileSystem.OpenRead(options.InputFilePath);
long firstResultStart = results.FindArrayStart(options.Index, inputStreamProvider);
long lastResultEnd = results.FindArrayStart(options.Index + options.Count, inputStreamProvider) - 1;
// Ensure output directory exists
string outputFolder = Path.GetDirectoryName(Path.GetFullPath(options.OutputFilePath));
Directory.CreateDirectory(outputFolder);
// Build the Sarif Log subset
long lengthWritten = 0;
byte[] buffer = new byte[64 * 1024];
using (Stream output = _fileSystem.Create(options.OutputFilePath))
using (Stream source = _fileSystem.OpenRead(options.InputFilePath))
{
// Copy everything up to 'runs' (includes the '[')
JsonMapNode.CopyStreamBytes(source, output, 0, runs.Start, buffer);
// In the run, copy everything to 'results' (includes the '[')
JsonMapNode.CopyStreamBytes(source, output, run.Start, results.Start, buffer);
// Find and copy the desired range of results, excluding the last ','
JsonMapNode.CopyStreamBytes(source, output, firstResultStart, lastResultEnd, buffer, omitFromLast: (byte)',');
// Copy everything after the results array to the end of the run (includes the '}')
JsonMapNode.CopyStreamBytes(source, output, results.End, run.End, buffer);
// Omit all subsequent runs
// Copy everything after all runs (includes runs ']' and log '}')
JsonMapNode.CopyStreamBytes(source, output, runs.End, root.End, buffer);
lengthWritten = output.Length;
}
w.Stop();
Console.WriteLine($"Done; wrote {(lengthWritten / (double)(1024 * 1024)):n2} MB in {w.Elapsed.TotalSeconds:n1}s.");
}