//**********************************************************************
// CSVCompare()
//
// Compare a field to a search value using a particular criteria.
//**********************************************************************
static bool CSVCompare(string fieldValue, string target, CSVCompareCriteria criteria)
{
if (criteria == CSVCompareCriteria.CC_ExactString)
{
return(fieldValue == target);
}
else if (criteria == CSVCompareCriteria.CC_ApproxString)
{
return(fieldValue.ToLower() == target.ToLower());
}
else if (criteria == CSVCompareCriteria.CC_Integer)
{
return(atoi(fieldValue) == atoi(target));
}
return(false);
}
//**********************************************************************
// CSVGetField()
//
// The all-in-one function to fetch a particular field value
// from a CSV file. Note this function will return an empty
// string, rather than NULL if it fails to find the desired
// value for some reason. The caller can't establish that the
// fetch failed.
//**********************************************************************
public static string CSVGetField(string filename, string keyFieldName, string keyFieldValue,
CSVCompareCriteria criteria, string targetField)
{
// --------------------------------------------------------------------
// Find the table.
// --------------------------------------------------------------------
CSVTable table = CSVAccess(filename);
if (table == null)
{
return("");
}
// --------------------------------------------------------------------
// Find the correct record.
// --------------------------------------------------------------------
string[] record = CSVScanFileByName(filename, keyFieldName, keyFieldValue, criteria);
if (record == null)
{
return("");
}
// --------------------------------------------------------------------
// Figure out which field we want out of this.
// --------------------------------------------------------------------
int iTargetField = CSVGetFileFieldId(filename, targetField);
if (iTargetField < 0)
{
return("");
}
if (iTargetField >= record.Length)
{
return("");
}
return(record[iTargetField]);
}
//**********************************************************************
// CSVGetField()
//
// The all-in-one function to fetch a particular field value
// from a CSV file. Note this function will return an empty
// string, rather than NULL if it fails to find the desired
// value for some reason. The caller can't establish that the
// fetch failed.
//**********************************************************************
public static string CSVGetField(string filename, string keyFieldName, string keyFieldValue,
CSVCompareCriteria criteria, string targetField)
{
// --------------------------------------------------------------------
// Find the table.
// --------------------------------------------------------------------
CSVTable table=CSVAccess(filename);
if(table==null) return "";
// --------------------------------------------------------------------
// Find the correct record.
// --------------------------------------------------------------------
string[] record=CSVScanFileByName(filename, keyFieldName, keyFieldValue, criteria);
if(record==null) return "";
// --------------------------------------------------------------------
// Figure out which field we want out of this.
// --------------------------------------------------------------------
int iTargetField=CSVGetFileFieldId(filename, targetField);
if(iTargetField<0) return "";
if(iTargetField>=record.Length) return "";
return record[iTargetField];
}
//**********************************************************************
// CSVScanFileByName()
//
// Same as CSVScanFile(), but using a field name instead of a
// field number.
//**********************************************************************
public static string[] CSVScanFileByName(string filename, string keyFieldName, string value, CSVCompareCriteria criteria)
{
int keyField=CSVGetFileFieldId(filename, keyFieldName);
if(keyField==-1) return null;
return CSVScanFile(filename, keyField, value, criteria);
}
//**********************************************************************
// CSVScanFile()
//
// Scan a whole file using criteria similar to above, but also
// taking care of file opening and closing.
//**********************************************************************
public static string[] CSVScanFile(string filename, int keyField, string value, CSVCompareCriteria criteria)
{
// --------------------------------------------------------------------
// Get access to the table.
// --------------------------------------------------------------------
if(keyField<0) return null;
CSVTable table=CSVAccess(filename);
if(table==null) return null;
CSVIngest(filename);
// --------------------------------------------------------------------
// Does the current record match the criteria? If so, just
// return it again.
// --------------------------------------------------------------------
if(keyField>=0&&keyField<table.recFields.Length&&CSVCompare(value, table.recFields[keyField], criteria))
return table.recFields;
// --------------------------------------------------------------------
// Scan the file from the beginning, replacing the "current
// record" in our structure with the one that is found.
// --------------------------------------------------------------------
if(table.cache!=null) table.recFields=CSVScanLinesIngested(table, keyField, value, criteria);
else
{
table.file.BaseStream.Seek(0, SeekOrigin.Begin);
CSVReadParseLine(table.file); // throw away the header line
table.recFields=CSVScanLines(table.file, keyField, value, criteria);
}
return table.recFields;
}
//**********************************************************************
// CSVScanLinesIngested()
//
// Read the file scanline for lines where the key field equals
// the indicated value with the suggested comparison criteria.
// Return the first matching line split into fields.
//**********************************************************************
static string[] CSVScanLinesIngested(CSVTable table, int keyField, string value, CSVCompareCriteria criteria)
{
int nTestValue=0;
if(criteria==CSVCompareCriteria.CC_Integer) nTestValue=atoi(value);
// --------------------------------------------------------------------
// Short cut for indexed files.
// --------------------------------------------------------------------
if(keyField==0&&criteria==CSVCompareCriteria.CC_Integer&&table.index!=null)
{
if(table.index.ContainsKey(nTestValue)) return table.index[nTestValue];
return null;
}
// --------------------------------------------------------------------
// Scan from in-core lines.
// --------------------------------------------------------------------
foreach(string[] line in table.cache)
{
if(line.Length<keyField+1) continue; // not selected
bool selected=false;
if(criteria==CSVCompareCriteria.CC_Integer&&atoi(line[keyField])==nTestValue)
selected=true;
else selected=CSVCompare(line[keyField], value, criteria);
if(selected) return line;
}
return null;
}
//**********************************************************************
// CSVScanLines()
//
// Read the file scanline for lines where the key field equals
// the indicated value with the suggested comparison criteria.
// Return the first matching line split into fields.
//**********************************************************************
public static string[] CSVScanLines(StreamReader file, int keyField, string value, CSVCompareCriteria criteria)
{
int testValue=atoi(value);
for(;;)
{
string[] fields=CSVReadParseLine(file);
if(fields==null) return null;
if(fields.Length<keyField+1) continue; // not selected
bool selected=false;
if(criteria==CSVCompareCriteria.CC_Integer&&atoi(fields[keyField])==testValue)
selected=true;
else selected=CSVCompare(fields[keyField], value, criteria);
if(selected) return fields;
}
}
//**********************************************************************
// CSVCompare()
//
// Compare a field to a search value using a particular criteria.
//**********************************************************************
static bool CSVCompare(string fieldValue, string target, CSVCompareCriteria criteria)
{
if(criteria==CSVCompareCriteria.CC_ExactString) return fieldValue==target;
else if(criteria==CSVCompareCriteria.CC_ApproxString) return fieldValue.ToLower()==target.ToLower();
else if(criteria==CSVCompareCriteria.CC_Integer) return atoi(fieldValue)==atoi(target);
return false;
}
//**********************************************************************
// CSVScanFileByName()
//
// Same as CSVScanFile(), but using a field name instead of a
// field number.
//**********************************************************************
public static string[] CSVScanFileByName(string filename, string keyFieldName, string value, CSVCompareCriteria criteria)
{
int keyField = CSVGetFileFieldId(filename, keyFieldName);
if (keyField == -1)
{
return(null);
}
return(CSVScanFile(filename, keyField, value, criteria));
}
//**********************************************************************
// CSVScanFile()
//
// Scan a whole file using criteria similar to above, but also
// taking care of file opening and closing.
//**********************************************************************
public static string[] CSVScanFile(string filename, int keyField, string value, CSVCompareCriteria criteria)
{
// --------------------------------------------------------------------
// Get access to the table.
// --------------------------------------------------------------------
if (keyField < 0)
{
return(null);
}
CSVTable table = CSVAccess(filename);
if (table == null)
{
return(null);
}
CSVIngest(filename);
// --------------------------------------------------------------------
// Does the current record match the criteria? If so, just
// return it again.
// --------------------------------------------------------------------
if (keyField >= 0 && keyField < table.recFields.Length && CSVCompare(value, table.recFields[keyField], criteria))
{
return(table.recFields);
}
// --------------------------------------------------------------------
// Scan the file from the beginning, replacing the "current
// record" in our structure with the one that is found.
// --------------------------------------------------------------------
if (table.cache != null)
{
table.recFields = CSVScanLinesIngested(table, keyField, value, criteria);
}
else
{
table.file.BaseStream.Seek(0, SeekOrigin.Begin);
CSVReadParseLine(table.file); // throw away the header line
table.recFields = CSVScanLines(table.file, keyField, value, criteria);
}
return(table.recFields);
}
//**********************************************************************
// CSVScanLinesIngested()
//
// Read the file scanline for lines where the key field equals
// the indicated value with the suggested comparison criteria.
// Return the first matching line split into fields.
//**********************************************************************
static string[] CSVScanLinesIngested(CSVTable table, int keyField, string value, CSVCompareCriteria criteria)
{
int nTestValue = 0;
if (criteria == CSVCompareCriteria.CC_Integer)
{
nTestValue = atoi(value);
}
// --------------------------------------------------------------------
// Short cut for indexed files.
// --------------------------------------------------------------------
if (keyField == 0 && criteria == CSVCompareCriteria.CC_Integer && table.index != null)
{
if (table.index.ContainsKey(nTestValue))
{
return(table.index[nTestValue]);
}
return(null);
}
// --------------------------------------------------------------------
// Scan from in-core lines.
// --------------------------------------------------------------------
foreach (string[] line in table.cache)
{
if (line.Length < keyField + 1)
{
continue; // not selected
}
bool selected = false;
if (criteria == CSVCompareCriteria.CC_Integer && atoi(line[keyField]) == nTestValue)
{
selected = true;
}
else
{
selected = CSVCompare(line[keyField], value, criteria);
}
if (selected)
{
return(line);
}
}
return(null);
}
//**********************************************************************
// CSVScanLines()
//
// Read the file scanline for lines where the key field equals
// the indicated value with the suggested comparison criteria.
// Return the first matching line split into fields.
//**********************************************************************
public static string[] CSVScanLines(StreamReader file, int keyField, string value, CSVCompareCriteria criteria)
{
int testValue = atoi(value);
for (;;)
{
string[] fields = CSVReadParseLine(file);
if (fields == null)
{
return(null);
}
if (fields.Length < keyField + 1)
{
continue; // not selected
}
bool selected = false;
if (criteria == CSVCompareCriteria.CC_Integer && atoi(fields[keyField]) == testValue)
{
selected = true;
}
else
{
selected = CSVCompare(fields[keyField], value, criteria);
}
if (selected)
{
return(fields);
}
}
}
