[
https://issues.apache.org/jira/browse/FLINK-10399?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16641964#comment-16641964
]
ASF GitHub Bot commented on FLINK-10399:
----------------------------------------
GJL commented on a change in pull request #6737: [FLINK-10399] Refactor
ParameterTool#fromArgs
URL: https://github.com/apache/flink/pull/6737#discussion_r223391917
##########
File path:
flink-java/src/main/java/org/apache/flink/api/java/utils/ParameterTool.java
##########
@@ -68,81 +68,46 @@
* @return A {@link ParameterTool}
*/
public static ParameterTool fromArgs(String[] args) {
- Map<String, String> map = new HashMap<String,
String>(args.length / 2);
-
- String key = null;
- String value = null;
- boolean expectValue = false;
- for (String arg : args) {
- // check for -- argument
- if (arg.startsWith("--")) {
- if (expectValue) {
- // we got into a new key, even though
we were a value --> current key is one without value
- if (value != null) {
- throw new
IllegalStateException("Unexpected state");
- }
- map.put(key, NO_VALUE_KEY);
- // key will be overwritten in the next
step
- }
- key = arg.substring(2);
- expectValue = true;
- } // check for - argument
- else if (arg.startsWith("-")) {
- // we are waiting for a value, so this is a -
prefixed value (negative number)
- if (expectValue) {
-
- if (NumberUtils.isNumber(arg)) {
- // negative number
- value = arg;
- expectValue = false;
- } else {
- if (value != null) {
- throw new
IllegalStateException("Unexpected state");
- }
- // We waited for a value but
found a new key. So the previous key doesnt have a value.
- map.put(key, NO_VALUE_KEY);
- key = arg.substring(1);
- expectValue = true;
- }
- } else {
- // we are not waiting for a value, so
its an argument
- key = arg.substring(1);
- expectValue = true;
- }
+ final Map<String, String> map = new HashMap<>(args.length / 2);
+
+ final String errorMessage = "Error parsing arguments '%s' on
'%s'.";
+
+ int i = 0;
+ while (i < args.length) {
+ final String key;
+
+ if (args[i].startsWith("--")) {
+ key = args[i].substring(2);
+ } else if (args[i].startsWith("-")) {
+ key = args[i].substring(1);
} else {
- if (expectValue) {
- value = arg;
- expectValue = false;
- } else {
- throw new RuntimeException("Error
parsing arguments '" + Arrays.toString(args) + "' on '" + arg + "'. Unexpected
value. Please prefix values with -- or -.");
- }
+ throw new IllegalArgumentException(
+ String.format(errorMessage + " Please
prefix keys with -- or -.",
+ Arrays.toString(args),
args[i]));
}
- if (value == null && key == null) {
- throw new IllegalStateException("Value and key
can not be null at the same time");
- }
- if (key != null && value == null && !expectValue) {
- throw new IllegalStateException("Value expected
but flag not set");
- }
- if (key != null && value != null) {
- map.put(key, value);
- key = null;
- value = null;
- expectValue = false;
- }
- if (key != null && key.length() == 0) {
- throw new IllegalArgumentException("The input "
+ Arrays.toString(args) + " contains an empty argument");
+ if (key.length() == 0) {
+ throw new IllegalArgumentException(
+ String.format(errorMessage + " Keys
should never be empty",
+ Arrays.toString(args),
args[i]));
}
- if (key != null && !expectValue) {
+ i += 1; // try to find the value
+
+ if (i >= args.length) {
+ map.put(key, NO_VALUE_KEY);
+ } else if (NumberUtils.isNumber(args[i])) {
+ map.put(key, args[i]);
+ i += 1;
+ } else if (args[i].startsWith("--")) {
+ map.put(key, NO_VALUE_KEY);
+ } else if (args[i].startsWith("-")) { // negate number
guarded by precondition
Review comment:
It's not clear to me what the comment means, and you have two branches that
are equal. Maybe rewrite to:
```
else if (args[i].startsWith("--") || args[i].startsWith("-")) {
// the argument cannot be a negative number because we checked earlier
// -> the next argument is a parameter name
map.put(key, NO_VALUE_KEY);
}
```
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> Refactor ParameterTool#fromArgs
> -------------------------------
>
> Key: FLINK-10399
> URL: https://issues.apache.org/jira/browse/FLINK-10399
> Project: Flink
> Issue Type: Improvement
> Components: Client
> Affects Versions: 1.7.0
> Reporter: TisonKun
> Assignee: TisonKun
> Priority: Major
> Labels: pull-request-available
> Fix For: 1.7.0
>
>
> {{ParameterTool#fromArgs}} uses a weird implement which flink developer would
> fail to parse it fast.
> The main problem is that, when parse args, we always try to get a key-value
> pair, but the implement iterate by a {{for}} loop, thus introduce weird
> flag/mutable variable and branches.
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