1 files changed, 247 insertions, 0 deletions
diff --git a/src/lib/util/versioned_csv_file.cc b/src/lib/util/versioned_csv_file.cc
new file mode 100644
index 0000000..8c48f66
--- /dev/null
+++ b/src/lib/util/versioned_csv_file.cc
@@ -0,0 +1,247 @@
+// Copyright (C) 2015-2021 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include <config.h>
+
+#include <util/versioned_csv_file.h>
+
+namespace isc {
+namespace util {
+
+VersionedCSVFile::VersionedCSVFile(const std::string& filename)
+    : CSVFile(filename), columns_(0), valid_column_count_(0),
+      minimum_valid_columns_(0), input_header_count_(0),
+      input_schema_state_(CURRENT) {
+}
+
+VersionedCSVFile::~VersionedCSVFile() {
+}
+
+void
+VersionedCSVFile::addColumn(const std::string& name,
+                            const std::string& version,
+                            const std::string& default_value) {
+    CSVFile::addColumn(name);
+    columns_.push_back(VersionedColumnPtr(new VersionedColumn(name, version,
+                                                              default_value)));
+}
+
+void
+VersionedCSVFile::setMinimumValidColumns(const std::string& column_name) {
+    try {
+        int index = getColumnIndex(column_name);
+        minimum_valid_columns_ = index + 1;
+
+    } catch (...) {
+        isc_throw(VersionedCSVFileError,
+                  "setMinimumValidColumns: " << column_name << " is not "
+                  "defined");
+    }
+}
+
+size_t
+VersionedCSVFile::getMinimumValidColumns() const {
+    return (minimum_valid_columns_);
+}
+
+size_t
+VersionedCSVFile::getValidColumnCount() const {
+    return (valid_column_count_);
+}
+
+size_t
+VersionedCSVFile::getInputHeaderCount() const {
+    return (input_header_count_);
+}
+
+void
+VersionedCSVFile::open(const bool seek_to_end) {
+    if (getColumnCount() == 0) {
+        isc_throw(VersionedCSVFileError,
+                  "no schema has been defined, cannot open CSV file :"
+                  << getFilename());
+    }
+
+    CSVFile::open(seek_to_end);
+}
+
+void
+VersionedCSVFile::recreate() {
+    if (getColumnCount() == 0) {
+        isc_throw(VersionedCSVFileError,
+                  "no schema has been defined, cannot create CSV file :"
+                  << getFilename());
+    }
+
+    CSVFile::recreate();
+    // For new files they always match.
+    input_header_count_ = valid_column_count_ = getColumnCount();
+}
+
+VersionedCSVFile::InputSchemaState
+VersionedCSVFile::getInputSchemaState() const {
+    return (input_schema_state_);
+}
+
+bool
+VersionedCSVFile::needsConversion() const {
+    return (input_schema_state_ != CURRENT);
+}
+
+std::string
+VersionedCSVFile::getInputSchemaVersion() const {
+    if (getValidColumnCount() > 0) {
+        return (getVersionedColumn(getValidColumnCount() - 1)->version_);
+    }
+
+    return ("undefined");
+}
+
+std::string
+VersionedCSVFile::getSchemaVersion() const {
+    if (getColumnCount() > 0) {
+        return (getVersionedColumn(getColumnCount() - 1)->version_);
+    }
+
+    return ("undefined");
+}
+
+const VersionedColumnPtr&
+VersionedCSVFile::getVersionedColumn(const size_t index) const {
+    if (index >= getColumnCount()) {
+        isc_throw(isc::OutOfRange, "versioned column index " << index
+                  << " out of range;  CSV file : " << getFilename()
+                  << " only has " << getColumnCount() << " columns ");
+    }
+
+    return (columns_[index]);
+}
+
+bool
+VersionedCSVFile::next(CSVRow& row) {
+    setReadMsg("success");
+    // Use base class to physical read the row, but skip its row
+    // validation
+    CSVFile::next(row, true);
+    if (row == CSVFile::EMPTY_ROW()) {
+        return(true);
+    }
+
+    bool row_valid = true;
+    switch(getInputSchemaState()) {
+        case CURRENT:
+            // All rows must match than the current schema
+            if (row.getValuesCount() != getColumnCount()) {
+                columnCountError(row, "must match current schema");
+                row_valid = false;
+            }
+            break;
+
+        case NEEDS_UPGRADE:
+            // The input header met the minimum column count but
+            // is less than the current schema so:
+            // Rows must not be shorter than the valid column count
+            // and not longer than the current schema
+            if (row.getValuesCount() < getValidColumnCount()) {
+                columnCountError(row, "too few columns to upgrade");
+                row_valid = false;
+            } else if (row.getValuesCount() > getColumnCount()) {
+                columnCountError(row, "too many columns to upgrade");
+                row_valid = false;
+            } else {
+                // Add any missing values
+                for (size_t index = row.getValuesCount();
+                     index < getColumnCount(); ++index) {
+                    row.append(columns_[index]->default_value_);
+                }
+            }
+            break;
+
+        case NEEDS_DOWNGRADE:
+            // The input header exceeded current schema so:
+            // Rows may be as long as input header but not shorter than
+            // the current schema
+            if (row.getValuesCount() < getColumnCount()) {
+                columnCountError(row, "too few columns to downgrade");
+            } else if (row.getValuesCount() > getInputHeaderCount()) {
+                columnCountError(row, "too many columns to downgrade");
+            } else {
+                // Toss any the extra columns
+                row.trim(row.getValuesCount() - getColumnCount());
+            }
+            break;
+    }
+
+    return (row_valid);
+}
+
+void
+VersionedCSVFile::columnCountError(const CSVRow& row,
+                                  const std::string& reason) {
+    std::ostringstream s;
+    s <<  "Invalid number of columns: "
+      << row.getValuesCount()  << " in row: '" << row
+      << "', file: '" << getFilename() << "' : " << reason;
+      setReadMsg(s.str());
+}
+
+bool
+VersionedCSVFile::validateHeader(const CSVRow& header) {
+    if (getColumnCount() == 0) {
+        isc_throw(VersionedCSVFileError,
+                  "cannot validate header, no schema has been defined");
+    }
+
+    input_header_count_ = header.getValuesCount();
+
+    // Iterate over the number of columns in the header, testing
+    // each against the defined column in the same position.
+    // If there is a mismatch, bail.
+    size_t i = 0;
+    for (  ; i < getInputHeaderCount() && i < getColumnCount(); ++i) {
+        if (getColumnName(i) != header.readAt(i)) {
+            std::ostringstream s;
+            s << " - header contains an invalid column: '"
+              << header.readAt(i) << "'";
+            setReadMsg(s.str());
+            return (false);
+        }
+    }
+
+    // If we found too few valid columns, then we cannot convert this
+    // file.  It's too old, too corrupt, or not a Kea file.
+    if (i < getMinimumValidColumns()) {
+        std::ostringstream s;
+        s << " - header has only " << i << " valid column(s), "
+          << "it must have at least " << getMinimumValidColumns();
+        setReadMsg(s.str());
+        return (false);
+    }
+
+    // Remember the number of valid columns we found.  When this number
+    // is less than the number of defined columns, then we have an older
+    // version of the lease file.  We'll need this value to validate
+    // and upgrade data rows.
+    valid_column_count_ = i;
+
+    if (getValidColumnCount() < getColumnCount()) {
+        input_schema_state_ = NEEDS_UPGRADE;
+    } else if (getInputHeaderCount() > getColumnCount()) {
+        // If there are more values in the header than defined columns
+        // then, we'll drop the extra.  This allows someone to attempt to
+        // downgrade if need be.
+        input_schema_state_ = NEEDS_DOWNGRADE;
+        std::ostringstream s;
+        s << " - header has " << getInputHeaderCount() - getColumnCount()
+          << " extra column(s), these will be ignored";
+        setReadMsg(s.str());
+    }
+
+    return (true);
+}
+
+} // end of isc::util namespace
+} // end of isc namespace