/// <summary>
/// Build the JsonMap for a given Json file, given a stream provider.
/// Returns null if the source file was too small for any map nodes to fit the size budget.
/// </summary>
/// <param name="streamProvider">A function which will open the stream for the desired file</param>
/// <param name="settings">JsonMapSettings for map; null for defaults</param>
/// <returns>JsonMap for file or null if file too small for map</returns>
public static JsonMapNode Build(Func <Stream> streamProvider, JsonMapSettings settings = null)
{
JsonMapRunSettings runSettings = null;
using (Stream stream = streamProvider())
{
long length = stream.Length;
// Compute JsonMapSettings for this specific file
runSettings = new JsonMapRunSettings(length, settings ?? JsonMapRunSettings.DefaultSettings);
// Don't build the map at all if the file is too small for anything to be mapped
if (length <= runSettings.MinimumSizeForNode)
{
return(null);
}
}
// Parse file using JsonPositionedTextReader so map can get byte locations of elements
using (JsonPositionedTextReader reader = new JsonPositionedTextReader(streamProvider))
{
if (!reader.Read())
{
return(null);
}
return(Build(reader, runSettings, startPosition: 0, out long _));
}
}
public JsonMapRunSettings(double fileSizeBytes, JsonMapSettings userSettings)
: base(userSettings.MapDesiredSizeRatio, userSettings.MapMaximumSizeBytes)
{
double expectedSize = fileSizeBytes * MapDesiredSizeRatio;
// Calculate real ratio to use for this file (desired if file size permits)
if (MapMaximumSizeBytes > 0 && expectedSize > MapMaximumSizeBytes)
{
CurrentSizeRatio = MapMaximumSizeBytes / fileSizeBytes;
}
else
{
CurrentSizeRatio = MapDesiredSizeRatio;
}
// Calculate the minimum node size which can fit into the map given the specific ratio
MinimumSizeForNode = (int)(NodeSizeEstimateBytes / CurrentSizeRatio);
}
/// <summary>
/// Build the JsonMap for a given Json file, by path.
/// Returns null if the source file was too small for any map nodes to fit the size budget.
/// </summary>
/// <param name="filePath">File Path to the Json file to build a map from</param>
/// <param name="settings">JsonMapSettings for map; null for defaults</param>
/// <returns>JsonMap for file or null if file too small for map</returns>
public static JsonMapNode Build(string filePath, JsonMapSettings settings = null)
{
return(Build(() => File.OpenRead(filePath), settings));
}