@Override
public boolean verify(Primary primary) {
if (!(primary instanceof TextPrimary)) throw new IllegalArgumentException();
TextPrimary textPrimary = (TextPrimary) primary;
byte[] digest = checkSum(textPrimary.getContent(), this.checkSumType);
return Arrays.equals(digest, this.checkSum);
}
// Constructor::TextContext
//
// Generates a TextContext Object.
//
// Generates before and after contexts based on given length and values
//
// Parameters
//
// * primary -- TextPrimary object to be tested against context
// * constraint -- TextConstraint object attached to this context
// * checkSumType -- Hash for checksum
// * contextLength - length (in chars) of the context used for testing
//
public TextContext(
TextPrimary primary, TextConstraint constraint, HashType checkSumType, int contextLength) {
super();
this.checkSumType = checkSumType;
// Testing if content matches the bit-checksum tests
this.checkSum = checkSum(primary.getContent(), checkSumType);
int beforeStart = constraint.getStartPos() - contextLength;
beforeStart = Math.max(0, beforeStart);
int beforeEnd = constraint.getStartPos();
int afterStart = constraint.getEndPos();
int afterEnd = constraint.getEndPos() + contextLength;
afterEnd = Math.min(primary.getContent().length(), afterEnd);
// Evaluating how much of selected text to store
this.totalSelectionLength = primary.getContent().length();
int cLength = this.totalSelectionLength;
if (this.totalSelectionLength > DEFAULT_CONTEXTLENGTH) {
double half = (double) (this.totalSelectionLength / 2);
cLength = (int) (Math.floor(half * percentStorage));
this.beginSel = primary.getContent().substring(beforeEnd, (beforeEnd + cLength));
this.endSel = primary.getContent().substring((afterStart - cLength), afterStart);
this.totalSelection = this.beginSel.concat(this.endSel);
} else {
// Use the entire selection
this.beginSel = "";
this.endSel = "";
this.totalSelection = primary.getContent();
}
this.beforeContext = primary.getContent().substring(beforeStart, beforeEnd);
this.afterContext = primary.getContent().substring(afterStart, afterEnd);
}
@Override
public Constraint match(Primary primary, TextConstraint originalConstraint)
throws Context.NoMatchFoundException {
if (!(primary instanceof TextPrimary)) throw new IllegalArgumentException();
TextPrimary textPrimary = (TextPrimary) primary;
// TextConstraint result = shingleCloudMatch(textPrimary.getContent());
TextConstraint result = exactMatch(textPrimary.getContent(), originalConstraint);
if (result == null) {
// perform fuzzy matching
result = gstMatch(textPrimary.getContent(), originalConstraint);
}
// sanity check
if (result.getEndPos() < result.getStartPos()) throw new Context.NoMatchFoundException();
return result;
}