internal static int Find(this IEditablePdfDocument document, int windowSize, Func <byte[], bool> matches, int start = 0)
{
var end = document.Length;
var pos = start;
var window = new byte[windowSize];
while (pos < end)
{
window.Insert(document.Read(pos));
if (matches(window))
{
return(pos);
}
pos++;
}
return(-1);
}
internal static int FindReverse(this IEditablePdfDocument document, int windowSize, Func <byte[], bool> matches, int start)
{
var end = 0;
var pos = start;
var window = new byte[windowSize];
while (pos != end)
{
window.InsertReverse(document.Read(pos));
if (matches(window))
{
return(pos);
}
pos--;
}
return(-1);
}
public decimal ReadVersion()
{
var content = _document.Encoding.GetString(_document.Read(0, _document.Find(2, window => window[0] == 10 && window[1] != 37)));
switch (content.Split('\n')[0])
{
case "%PDF-1.4": return(1.4M);
default: throw new Exception("Invalid document");
}
;
}
internal static bool ByteEquals(this IEditablePdfDocument a, int posA, byte[] b, int posB) => a.Read(posA, b.Length - posB).ByteEquals(0, b, posB);