private void checkRecord(Type eltType, Record record, IEvaluatorContext ctx) {
// TODO: not all inconsistencies are detected yet
// probably because absent values get type void
// but are nevertheless initialized eventually
// to 0, false, or "".
if (record.getType().isSubtypeOf(eltType)) {
return;
}
if (eltType.isTuple()) {
int expectedArity = eltType.getArity();
int actualArity = record.getType().getArity();
if (expectedArity == actualArity) {
return;
}
throw RuntimeExceptionFactory.illegalTypeArgument(
"Arities of actual type and requested type are different ("
+ actualArity
+ " vs "
+ expectedArity
+ ")",
ctx.getCurrentAST(),
ctx.getStackTrace());
}
throw RuntimeExceptionFactory.illegalTypeArgument(
"Invalid tuple " + record + " for requested field " + eltType,
ctx.getCurrentAST(),
ctx.getStackTrace());
}
private IValue read(Type resultType, ISourceLocation loc, IMap options, IEvaluatorContext ctx) {
setOptions(options);
Reader reader = null;
try {
reader = ctx.getResolverRegistry().getCharacterReader(loc.getURI());
List<Record> records = loadRecords(reader);
if (resultType == null) {
resultType = inferType(records, ctx);
ctx.getStdOut().println("readCSV inferred the relation type: " + resultType);
ctx.getStdOut().flush();
} else if (header) {
records.remove(0);
}
return buildCollection(resultType, records, ctx);
} catch (IOException e) {
throw RuntimeExceptionFactory.io(
values.string(e.getMessage()), ctx.getCurrentAST(), ctx.getStackTrace());
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
throw RuntimeExceptionFactory.io(
values.string(e.getMessage()), ctx.getCurrentAST(), ctx.getStackTrace());
}
}
}
}
public IValue buildCollection(Type type, List<Record> records, IEvaluatorContext ctx) {
IWriter writer;
while (type.isAliased()) {
type = type.getAliased();
}
if (type.isList()) {
writer = values.listWriter(type.getElementType());
} else if (type.isRelation()) {
writer = values.relationWriter(type.getElementType());
} else {
throw RuntimeExceptionFactory.illegalTypeArgument(
"Invalid result type for CSV reading: " + type, ctx.getCurrentAST(), ctx.getStackTrace());
}
// reverse traversal so that the order in case of ListWriter is correct
// (IWriter only supports inserts at the front).
Type eltType = type.getElementType();
for (int i = records.size() - 1; i >= 0; i--) {
Record record = records.get(i);
checkRecord(eltType, record, ctx);
writer.insert(record.getTuple(eltType));
}
return writer.done();
}
private Type inferType(List<Record> records, IEvaluatorContext ctx) throws IOException {
String[] labels = null;
if (header) {
labels = extractLabels(records.remove(0));
}
Type[] fieldTypes = null;
for (Record ri : records) {
List<Type> ftypes = ri.getFieldTypes();
if (fieldTypes == null) {
fieldTypes = new Type[ftypes.size()];
Arrays.fill(fieldTypes, types.voidType());
} else if (ftypes.size() != fieldTypes.length) {
// We assume all records in the CSV file to have the same arity.
throw RuntimeExceptionFactory.illegalArgument(
// "Inconsistent tuple in CSV expected " + fieldTypes.length + " but was " +
// ftypes.size(),
ctx.getCurrentAST(), ctx.getStackTrace());
}
for (int i = 0; i < ftypes.size(); i++) {
fieldTypes[i] = fieldTypes[i].lub(ftypes.get(i));
if (fieldTypes[i].isTop()) {
fieldTypes[i] = types.stringType();
}
}
}
if (labels == null) {
labels = makeUpLabels(fieldTypes.length);
}
return types.setType(types.tupleType(fieldTypes, labels));
}
public void write(IValue rel, ISourceLocation loc, IEvaluatorContext ctx) {
OutputStream out = null;
Type paramType = ctx.getCurrentEnvt().getTypeBindings().get(types.parameterType("T"));
if (!paramType.isRelation() && !paramType.isListRelation()) {
throw RuntimeExceptionFactory.illegalTypeArgument(
"A relation type is required instead of " + paramType,
ctx.getCurrentAST(),
ctx.getStackTrace());
}
try {
boolean isListRel = rel instanceof IList;
out = ctx.getResolverRegistry().getOutputStream(loc.getURI(), false);
ISet irel = null;
IList lrel = null;
if (isListRel) {
lrel = (IList) rel;
} else {
irel = (ISet) rel;
}
int nfields = isListRel ? lrel.asRelation().arity() : irel.asRelation().arity();
if (header) {
for (int i = 0; i < nfields; i++) {
if (i > 0) out.write(separator);
String label = paramType.getFieldName(i);
if (label == null || label.isEmpty()) label = "field" + i;
writeString(out, label);
}
out.write('\n');
}
String separatorAsString = new String(Character.toChars(separator));
for (IValue v : (isListRel ? lrel : irel)) {
ITuple tup = (ITuple) v;
int sep = 0;
for (IValue w : tup) {
if (sep == 0) sep = separator;
else out.write(sep);
if (w.getType().isString()) {
String s = ((IString) w).getValue();
if (s.contains(separatorAsString)
|| s.contains("\n")
|| s.contains("\r")
|| s.contains("\"")) {
s = s.replaceAll("\"", "\"\"");
out.write('"');
writeString(out, s);
out.write('"');
} else writeString(out, s);
} else {
writeString(out, w.toString());
}
}
out.write('\n');
}
out.flush();
out.close();
} catch (IOException e) {
throw RuntimeExceptionFactory.io(values.string(e.getMessage()), null, null);
} finally {
if (out != null) {
try {
out.flush();
out.close();
} catch (IOException ioex) {
throw RuntimeExceptionFactory.io(values.string(ioex.getMessage()), null, null);
}
}
}
}