private void BuildPositions()
{
using (Stream stream = _streamProvider())
using (JsonPositionedTextReader reader = new JsonPositionedTextReader(() => stream))
{
stream.Seek(_start, SeekOrigin.Begin);
reader.Read();
BuildPositions(reader, _start);
}
}
private void CountOnly(JsonPositionedTextReader reader)
{
int count = 0;
// StartArray
reader.Read();
while (true)
{
reader.Read();
if (reader.TokenType == JsonToken.EndArray)
{
break;
}
count++;
reader.Skip();
}
_count = count;
}
private void BuildPositions(JsonPositionedTextReader reader, long currentOffset)
{
var result = new Dictionary <int, long>();
while (true)
{
// Find the position just before the PropertyName (we need to read it back later to confirm the string matches)
long keyPosition = currentOffset + reader.TokenPosition + 1;
reader.Read();
if (reader.TokenType == JsonToken.EndObject)
{
break;
}
if (reader.TokenType != JsonToken.PropertyName)
{
throw new InvalidDataException($"@({reader.LineNumber}, {reader.LinePosition}): Expected property name, found {reader.TokenType} \"{reader.Value}\".");
}
// Read JSON object name (Dictionary key)
string key = (string)reader.Value;
int keyHash = key.GetHashCode();
// Skip the value
reader.Read();
reader.Skip();
// Add the hash to the position to our Dictionary; resolve collisions by incrementing
while (result.ContainsKey(keyHash))
{
keyHash++;
}
result[keyHash] = keyPosition;
}
_itemPositions = result;
}
private void BuildPositions(JsonPositionedTextReader reader, long currentOffset)
{
List <long> positions = new List <long>();
while (true)
{
reader.Read();
if (reader.TokenType == JsonToken.EndArray)
{
break;
}
positions.Add(currentOffset + reader.TokenPosition);
reader.Skip();
}
_itemPositions = positions.ToArray();
_count = positions.Count;
}