com.datastax.oss.driver.internal.core.metadata.schema.queries.RuleBasedKeyspaceFilter Maven / Gradle / Ivy
/*
* Copyright DataStax, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.datastax.oss.driver.internal.core.metadata.schema.queries;
import com.datastax.oss.driver.api.core.config.DefaultDriverOption;
import edu.umd.cs.findbugs.annotations.NonNull;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import java.util.function.Predicate;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Filters keyspaces during schema metadata queries.
*
* Depending on the circumstances, we do it either on the server side with a WHERE IN clause that
* will be appended to every query, or on the client side with a predicate that will be applied to
* every fetched row.
*/
class RuleBasedKeyspaceFilter implements KeyspaceFilter {
private static final Logger LOG = LoggerFactory.getLogger(RuleBasedKeyspaceFilter.class);
private static final Pattern EXACT_INCLUDE = Pattern.compile("\\w+");
private static final Pattern EXACT_EXCLUDE = Pattern.compile("!\\s*(\\w+)");
private static final Pattern REGEX_INCLUDE = Pattern.compile("/(.+)/");
private static final Pattern REGEX_EXCLUDE = Pattern.compile("!\\s*/(.+)/");
private final String logPrefix;
private final String whereClause;
private final Set exactIncludes = new HashSet<>();
private final Set exactExcludes = new HashSet<>();
private final List> regexIncludes = new ArrayList<>();
private final List> regexExcludes = new ArrayList<>();
private final boolean isDebugEnabled;
private final Set loggedKeyspaces;
RuleBasedKeyspaceFilter(@NonNull String logPrefix, @NonNull List specs) {
assert !specs.isEmpty(); // see KeyspaceFilter#newInstance
this.logPrefix = logPrefix;
for (String spec : specs) {
spec = spec.trim();
Matcher matcher;
if (EXACT_INCLUDE.matcher(spec).matches()) {
exactIncludes.add(spec);
if (exactExcludes.remove(spec)) {
LOG.warn(
"[{}] '{}' is both included and excluded, ignoring the exclusion", logPrefix, spec);
}
} else if ((matcher = EXACT_EXCLUDE.matcher(spec)).matches()) {
String name = matcher.group(1);
if (exactIncludes.contains(name)) {
LOG.warn(
"[{}] '{}' is both included and excluded, ignoring the exclusion", logPrefix, name);
} else {
exactExcludes.add(name);
}
} else if ((matcher = REGEX_INCLUDE.matcher(spec)).matches()) {
compile(matcher.group(1)).map(regexIncludes::add);
} else if ((matcher = REGEX_EXCLUDE.matcher(spec)).matches()) {
compile(matcher.group(1)).map(regexExcludes::add);
} else {
LOG.warn(
"[{}] Error while parsing {}: invalid element '{}', skipping",
logPrefix,
DefaultDriverOption.METADATA_SCHEMA_REFRESHED_KEYSPACES.getPath(),
spec);
}
}
if (!exactIncludes.isEmpty() && regexIncludes.isEmpty() && regexExcludes.isEmpty()) {
// We can filter on the server
whereClause = buildWhereClause(exactIncludes);
if (!exactExcludes.isEmpty()) {
// Proceed, but this is probably a mistake
LOG.warn(
"[{}] {} only has exact includes and excludes, the excludes are redundant",
logPrefix,
DefaultDriverOption.METADATA_SCHEMA_REFRESHED_KEYSPACES.getPath());
}
LOG.debug("[{}] Filtering server-side with '{}'", logPrefix, whereClause);
} else {
whereClause = "";
LOG.debug("[{}] No server-side filtering", logPrefix);
}
isDebugEnabled = LOG.isDebugEnabled();
loggedKeyspaces = isDebugEnabled ? new HashSet<>() : null;
}
@NonNull
@Override
public String getWhereClause() {
return whereClause;
}
@Override
public boolean includes(@NonNull String keyspace) {
if (exactIncludes.contains(keyspace)) {
log(keyspace, true, "it is included by name");
return true;
} else if (exactExcludes.contains(keyspace)) {
log(keyspace, false, "it is excluded by name");
return false;
} else if (regexIncludes.isEmpty()) {
if (regexExcludes.isEmpty()) {
log(keyspace, false, "it is not included by name");
return false;
} else if (matchesAny(keyspace, regexExcludes)) {
log(keyspace, false, "it matches at least one regex exclude");
return false;
} else {
log(keyspace, true, "it does not match any regex exclude");
return true;
}
} else { // !regexIncludes.isEmpty()
if (regexExcludes.isEmpty()) {
if (matchesAny(keyspace, regexIncludes)) {
log(keyspace, true, "it matches at least one regex include");
return true;
} else {
log(keyspace, false, "it does not match any regex include");
return false;
}
} else {
if (matchesAny(keyspace, regexIncludes) && !matchesAny(keyspace, regexExcludes)) {
log(keyspace, true, "it matches at least one regex include, and no regex exclude");
return true;
} else {
log(keyspace, false, "it matches either no regex include, or at least one regex exclude");
return false;
}
}
}
}
private void log(@NonNull String keyspace, boolean include, @NonNull String reason) {
if (isDebugEnabled && loggedKeyspaces.add(keyspace)) {
LOG.debug(
"[{}] Filtering {} '{}' because {}", logPrefix, include ? "in" : "out", keyspace, reason);
}
}
private boolean matchesAny(String keyspace, List> rules) {
for (Predicate rule : rules) {
if (rule.test(keyspace)) {
return true;
}
}
return false;
}
private Optional> compile(String regex) {
try {
return Optional.of(Pattern.compile(regex).asPredicate());
} catch (PatternSyntaxException e) {
LOG.warn(
"[{}] Error while parsing {}: syntax error in regex /{}/ ({}), skipping",
this.logPrefix,
DefaultDriverOption.METADATA_SCHEMA_REFRESHED_KEYSPACES.getPath(),
regex,
e.getMessage());
return Optional.empty();
}
}
private static String buildWhereClause(Set keyspaces) {
StringBuilder builder = new StringBuilder(" WHERE keyspace_name IN (");
boolean first = true;
for (String keyspace : keyspaces) {
if (first) {
first = false;
} else {
builder.append(",");
}
builder.append('\'').append(keyspace).append('\'');
}
return builder.append(')').toString();
}
}