[MRESOLVER-414] Fully split update policies internally

maven-resolver-api/src/main/java/org/eclipse/aether/AbstractForwardingRepositorySystemSession.java

@@ -86,6 +86,11 @@ public String getUpdatePolicy() {
         return getSession().getUpdatePolicy();
     }
 
+    @Override
+    public String getArtifactUpdatePolicy() {
+        return getSession().getArtifactUpdatePolicy();
+    }
+
     @Override
     public String getMetadataUpdatePolicy() {
         return getSession().getMetadataUpdatePolicy();

maven-resolver-api/src/main/java/org/eclipse/aether/DefaultRepositorySystemSession.java

@@ -67,7 +67,7 @@ public final class DefaultRepositorySystemSession implements RepositorySystemSes
 
     private String checksumPolicy;
 
-    private String updatePolicy;
+    private String artifactUpdatePolicy;
 
     private String metadataUpdatePolicy;
 
@@ -269,22 +269,52 @@ public DefaultRepositorySystemSession setChecksumPolicy(String checksumPolicy) {
 
     @Override
     public String getUpdatePolicy() {
-        return updatePolicy;
+        return getArtifactUpdatePolicy();
     }
 
     /**
      * Sets the global update policy. If set, the global update policy overrides the update policies of the remote
      * repositories being used for resolution.
+     * <p>
+     * This method is meant for code that does not want to distinguish between artifact and metadata policies.
+     * Note: applications should either use get/set updatePolicy (this method and
+     * {@link RepositorySystemSession#getUpdatePolicy()}) or also distinguish between artifact and
+     * metadata update policies (and use other methods), but <em>should not mix the two!</em>
      *
      * @param updatePolicy The global update policy, may be {@code null}/empty to apply the per-repository policies.
      * @return This session for chaining, never {@code null}.
      * @see RepositoryPolicy#UPDATE_POLICY_ALWAYS
      * @see RepositoryPolicy#UPDATE_POLICY_DAILY
      * @see RepositoryPolicy#UPDATE_POLICY_NEVER
+     * @see #setArtifactUpdatePolicy(String)
+     * @see #setMetadataUpdatePolicy(String)
      */
     public DefaultRepositorySystemSession setUpdatePolicy(String updatePolicy) {
         verifyStateForMutation();
-        this.updatePolicy = updatePolicy;
+        setArtifactUpdatePolicy(updatePolicy);
+        setMetadataUpdatePolicy(updatePolicy);
+        return this;
+    }
+
+    @Override
+    public String getArtifactUpdatePolicy() {
+        return artifactUpdatePolicy;
+    }
+
+    /**
+     * Sets the global artifact update policy. If set, the global update policy overrides the artifact update policies
+     * of the remote repositories being used for resolution.
+     *
+     * @param artifactUpdatePolicy The global update policy, may be {@code null}/empty to apply the per-repository policies.
+     * @return This session for chaining, never {@code null}.
+     * @see RepositoryPolicy#UPDATE_POLICY_ALWAYS
+     * @see RepositoryPolicy#UPDATE_POLICY_DAILY
+     * @see RepositoryPolicy#UPDATE_POLICY_NEVER
+     * @since TBD
+     */
+    public DefaultRepositorySystemSession setArtifactUpdatePolicy(String artifactUpdatePolicy) {
+        verifyStateForMutation();
+        this.artifactUpdatePolicy = artifactUpdatePolicy;
         return this;
     }
 
@@ -294,8 +324,8 @@ public String getMetadataUpdatePolicy() {
     }
 
     /**
-     * Sets the global metadata update policy. If set, the global update policy overrides the update policies of the remote
-     * repositories being used for resolution.
+     * Sets the global metadata update policy. If set, the global update policy overrides the metadata update policies
+     * of the remote repositories being used for resolution.
      *
      * @param metadataUpdatePolicy The global update policy, may be {@code null}/empty to apply the per-repository policies.
      * @return This session for chaining, never {@code null}.

maven-resolver-api/src/main/java/org/eclipse/aether/RepositorySystemSession.java

@@ -93,15 +93,29 @@ public interface RepositorySystemSession {
     String getChecksumPolicy();
 
     /**
-     * Gets the global data update policy. If set, the global update policy overrides the update policies of the remote
-     * repositories being used for resolution.
+     * Gets the global update policy, or {@code null} if not set.
+     * <p>
+     * This method is meant for code that does not want to distinguish between artifact and metadata policies.
+     * Note: applications should either use get/set updatePolicy (this method and
+     * {@link DefaultRepositorySystemSession#setUpdatePolicy(String)}) or also distinguish between artifact and
+     * metadata update policies (and use other methods), but <em>should not mix the two!</em>
+     *
+     * @see #getArtifactUpdatePolicy()
+     * @see #getMetadataUpdatePolicy()
+     */
+    String getUpdatePolicy();
+
+    /**
+     * Gets the global artifact update policy. If set, the global update policy overrides the update policies of the
+     * remote repositories being used for resolution.
      *
      * @return The global update policy or {@code null}/empty if not set and the per-repository policies apply.
      * @see RepositoryPolicy#UPDATE_POLICY_ALWAYS
      * @see RepositoryPolicy#UPDATE_POLICY_DAILY
      * @see RepositoryPolicy#UPDATE_POLICY_NEVER
+     * @since TBD
      */
-    String getUpdatePolicy();
+    String getArtifactUpdatePolicy();
 
     /**
      * Gets the global metadata update policy. If set, the global update policy overrides the update policies of the remote

maven-resolver-api/src/main/java/org/eclipse/aether/repository/RepositoryPolicy.java

@@ -60,7 +60,7 @@ public final class RepositoryPolicy {
 
     private final boolean enabled;
 
-    private final String updatePolicy;
+    private final String artifactUpdatePolicy;
 
     private final String metadataUpdatePolicy;
 
@@ -85,16 +85,17 @@ public RepositoryPolicy(boolean enabled, String updatePolicy, String checksumPol
      * Creates a new policy with the specified settings.
      *
      * @param enabled A flag whether the associated repository should be accessed or not.
-     * @param updatePolicy The update interval after which locally cached data from the repository is considered stale
+     * @param artifactUpdatePolicy The update interval after which locally cached data from the repository is considered stale
      *            and should be re-fetched, may be {@code null}.
      * @param metadataUpdatePolicy The update interval after which locally cached metadata from the repository is considered stale
      *            and should be re-fetched, may be {@code null}.
      * @param checksumPolicy The way checksum verification should be handled, may be {@code null}.
      * @since TBD
      */
-    public RepositoryPolicy(boolean enabled, String updatePolicy, String metadataUpdatePolicy, String checksumPolicy) {
+    public RepositoryPolicy(
+            boolean enabled, String artifactUpdatePolicy, String metadataUpdatePolicy, String checksumPolicy) {
         this.enabled = enabled;
-        this.updatePolicy = (updatePolicy != null) ? updatePolicy : "";
+        this.artifactUpdatePolicy = (artifactUpdatePolicy != null) ? artifactUpdatePolicy : "";
         this.metadataUpdatePolicy = (metadataUpdatePolicy != null) ? metadataUpdatePolicy : "";
         this.checksumPolicy = (checksumPolicy != null) ? checksumPolicy : "";
     }
@@ -109,12 +110,28 @@ public boolean isEnabled() {
     }
 
     /**
-     * Gets the update policy for locally cached data from the repository.
+     * This method is not used in Resolver, as resolver internally strictly distinguishes between artifact and metadata
+     * update policies.
      *
-     * @return The update policy, never {@code null}.
+     * @see #getArtifactUpdatePolicy()
+     * @see #getMetadataUpdatePolicy()
+     * @deprecated This method should not be used. Since version 2 Resolver internally distinguishes between artifact
+     * update policy and metadata update policy. This method was left only to preserve binary compatibility, and in
+     * reality invokes {@link #getArtifactUpdatePolicy()}.
      */
+    @Deprecated
     public String getUpdatePolicy() {
-        return updatePolicy;
+        return getArtifactUpdatePolicy();
+    }
+
+    /**
+     * Gets the update policy for locally cached artifacts from the repository.
+     *
+     * @return The update policy, never {@code null}.
+     * @since TBD
+     */
+    public String getArtifactUpdatePolicy() {
+        return artifactUpdatePolicy;
     }
 
     /**
@@ -140,7 +157,7 @@ public String getChecksumPolicy() {
     public String toString() {
         return "enabled=" + isEnabled()
                 + ", checksums=" + getChecksumPolicy()
-                + ", updates=" + getUpdatePolicy()
+                + ", artifactUpdates=" + getArtifactUpdatePolicy()
                 + ", metadataUpdates=" + getMetadataUpdatePolicy();
     }
 
@@ -157,15 +174,17 @@ public boolean equals(Object obj) {
         RepositoryPolicy that = (RepositoryPolicy) obj;
 
         return enabled == that.enabled
-                && updatePolicy.equals(that.updatePolicy)
+                && artifactUpdatePolicy.equals(that.artifactUpdatePolicy)
+                && metadataUpdatePolicy.equals(that.metadataUpdatePolicy)
                 && checksumPolicy.equals(that.checksumPolicy);
     }
 
     @Override
     public int hashCode() {
         int hash = 17;
         hash = hash * 31 + (enabled ? 1 : 0);
-        hash = hash * 31 + updatePolicy.hashCode();
+        hash = hash * 31 + artifactUpdatePolicy.hashCode();
+        hash = hash * 31 + metadataUpdatePolicy.hashCode();
         hash = hash * 31 + checksumPolicy.hashCode();
         return hash;
     }

maven-resolver-impl/src/main/java/org/eclipse/aether/impl/UpdateCheck.java

@@ -41,7 +41,7 @@ public final class UpdateCheck<T, E extends RepositoryException> {
 
     private boolean fileValid = true;
 
-    private String policy;
+    private String artifactPolicy;
 
     private String metadataPolicy;
 
@@ -149,13 +149,14 @@ public UpdateCheck<T, E> setFileValid(boolean fileValid) {
     }
 
     /**
-     * Gets the policy to use for the data check.
+     * Gets the policy to use for the artifact check.
      *
-     * @return The policy to use for the data check.
+     * @return The policy to use for the artifact check.
      * @see org.eclipse.aether.repository.RepositoryPolicy
+     * @since TBD
      */
-    public String getPolicy() {
-        return policy;
+    public String getArtifactPolicy() {
+        return artifactPolicy;
     }
 
     /**
@@ -170,19 +171,20 @@ public String getMetadataPolicy() {
     }
 
     /**
-     * Sets the policy to use for the check.
+     * Sets the artifact policy to use for the check.
      *
-     * @param policy The policy to use for the data check, may be {@code null}.
+     * @param artifactPolicy The policy to use for the artifact check, may be {@code null}.
      * @return This object for chaining.
      * @see org.eclipse.aether.repository.RepositoryPolicy
+     * @since TBD
      */
-    public UpdateCheck<T, E> setPolicy(String policy) {
-        this.policy = policy;
+    public UpdateCheck<T, E> setArtifactPolicy(String artifactPolicy) {
+        this.artifactPolicy = artifactPolicy;
         return this;
     }
 
     /**
-     * Sets the policy to use for the check.
+     * Sets the metadata policy to use for the check.
      *
      * @param metadataPolicy The policy to use for the metadata check, may be {@code null}.
      * @return This object for chaining.
@@ -282,6 +284,6 @@ public UpdateCheck<T, E> setException(E exception) {
 
     @Override
     public String toString() {
-        return getPolicy() + "/" + getMetadataPolicy() + ": " + getFile() + " < " + getRepository();
+        return getArtifactPolicy() + "/" + getMetadataPolicy() + ": " + getFile() + " < " + getRepository();
     }
 }

maven-resolver-impl/src/main/java/org/eclipse/aether/internal/impl/DefaultArtifactResolver.java

@@ -501,7 +501,7 @@ private List<ArtifactDownload> gatherDownloads(RepositorySystemSession session,
                 check.setFile(download.getFile());
                 check.setFileValid(false);
                 check.setRepository(group.repository);
-                check.setPolicy(policy.getUpdatePolicy());
+                check.setArtifactPolicy(policy.getArtifactUpdatePolicy());
                 check.setMetadataPolicy(policy.getMetadataUpdatePolicy());
                 item.updateCheck = check;
                 updateCheckManager.checkArtifact(session, check);

maven-resolver-impl/src/main/java/org/eclipse/aether/internal/impl/DefaultMetadataResolver.java

@@ -243,7 +243,7 @@ private List<MetadataResult> resolve(
                         check.setFile(checkFile);
                         check.setRepository(repository);
                         check.setAuthoritativeRepository(repo);
-                        check.setPolicy(policy.getUpdatePolicy());
+                        check.setArtifactPolicy(policy.getArtifactUpdatePolicy());
                         check.setMetadataPolicy(policy.getMetadataUpdatePolicy());
 
                         if (lrmResult.isStale()) {

maven-resolver-impl/src/main/java/org/eclipse/aether/internal/impl/DefaultRemoteRepositoryManager.java

@@ -238,7 +238,7 @@ private RepositoryPolicy merge(
             if (globalPolicy) {
                 policy = merge(
                         policy1,
-                        session.getUpdatePolicy(),
+                        session.getArtifactUpdatePolicy(),
                         session.getMetadataUpdatePolicy(),
                         session.getChecksumPolicy());
             } else {
@@ -248,7 +248,7 @@ private RepositoryPolicy merge(
             if (globalPolicy) {
                 policy = merge(
                         policy2,
-                        session.getUpdatePolicy(),
+                        session.getArtifactUpdatePolicy(),
                         session.getMetadataUpdatePolicy(),
                         session.getChecksumPolicy());
             } else {
@@ -258,7 +258,7 @@ private RepositoryPolicy merge(
             if (globalPolicy) {
                 policy = merge(
                         policy1,
-                        session.getUpdatePolicy(),
+                        session.getArtifactUpdatePolicy(),
                         session.getMetadataUpdatePolicy(),
                         session.getChecksumPolicy());
             } else {
@@ -268,7 +268,7 @@ private RepositoryPolicy merge(
             if (globalPolicy) {
                 policy = merge(
                         policy2,
-                        session.getUpdatePolicy(),
+                        session.getArtifactUpdatePolicy(),
                         session.getMetadataUpdatePolicy(),
                         session.getChecksumPolicy());
             } else {
@@ -284,13 +284,13 @@ private RepositoryPolicy merge(
                         session, policy1.getChecksumPolicy(), policy2.getChecksumPolicy());
             }
 
-            String updates = session.getUpdatePolicy();
+            String artifactUpdates = session.getArtifactUpdatePolicy();
             //noinspection StatementWithEmptyBody
-            if (globalPolicy && updates != null && !updates.isEmpty()) {
+            if (globalPolicy && artifactUpdates != null && !artifactUpdates.isEmpty()) {
                 // use global override
             } else {
-                updates = updatePolicyAnalyzer.getEffectiveUpdatePolicy(
-                        session, policy1.getUpdatePolicy(), policy2.getUpdatePolicy());
+                artifactUpdates = updatePolicyAnalyzer.getEffectiveUpdatePolicy(
+                        session, policy1.getArtifactUpdatePolicy(), policy2.getArtifactUpdatePolicy());
             }
             String metadataUpdates = session.getMetadataUpdatePolicy();
             if (globalPolicy && metadataUpdates != null && !metadataUpdates.isEmpty()) {
@@ -300,27 +300,28 @@ private RepositoryPolicy merge(
                         session, policy1.getMetadataUpdatePolicy(), policy2.getMetadataUpdatePolicy());
             }
 
-            policy = new RepositoryPolicy(true, updates, metadataUpdates, checksums);
+            policy = new RepositoryPolicy(true, artifactUpdates, metadataUpdates, checksums);
         }
 
         return policy;
     }
 
-    private RepositoryPolicy merge(RepositoryPolicy policy, String updates, String metadataUpdates, String checksums) {
+    private RepositoryPolicy merge(
+            RepositoryPolicy policy, String artifactUpdates, String metadataUpdates, String checksums) {
         if (policy != null) {
-            if (updates == null || updates.isEmpty()) {
-                updates = policy.getUpdatePolicy();
+            if (artifactUpdates == null || artifactUpdates.isEmpty()) {
+                artifactUpdates = policy.getArtifactUpdatePolicy();
             }
             if (metadataUpdates == null || metadataUpdates.isEmpty()) {
                 metadataUpdates = policy.getMetadataUpdatePolicy();
             }
             if (checksums == null || checksums.isEmpty()) {
                 checksums = policy.getChecksumPolicy();
             }
-            if (!policy.getUpdatePolicy().equals(updates)
+            if (!policy.getArtifactUpdatePolicy().equals(artifactUpdates)
                     || !policy.getMetadataUpdatePolicy().equals(metadataUpdates)
                     || !policy.getChecksumPolicy().equals(checksums)) {
-                policy = new RepositoryPolicy(policy.isEnabled(), updates, metadataUpdates, checksums);
+                policy = new RepositoryPolicy(policy.isEnabled(), artifactUpdates, metadataUpdates, checksums);
             }
         }
         return policy;

maven-resolver-impl/src/main/java/org/eclipse/aether/internal/impl/DefaultUpdateCheckManager.java

@@ -115,7 +115,7 @@ public DefaultUpdateCheckManager(
     public void checkArtifact(RepositorySystemSession session, UpdateCheck<Artifact, ArtifactTransferException> check) {
         requireNonNull(session, "session cannot be null");
         requireNonNull(check, "check cannot be null");
-        final String updatePolicy = check.getPolicy();
+        final String updatePolicy = check.getArtifactPolicy();
         if (check.getLocalLastUpdated() != 0
                 && !isUpdatedRequired(session, check.getLocalLastUpdated(), updatePolicy)) {
             LOGGER.debug("Skipped remote request for {}, locally installed artifact up-to-date", check.getItem());