Moves loading of accounts, notifications, and statuses to use link headers. Also remedies an issue where duplicate calls for the same chunk of items in a list can occur.

app/src/main/java/com/keylesspalace/tusky/util/HttpHeaderLink.java

@@ -0,0 +1,148 @@
+/* Written in 2017 by Andrew Dawson
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright and related and
+ * neighboring rights to this software to the public domain worldwide. This software is distributed
+ * without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along with this software.
+ * If not, see <http://creativecommons.org/publicdomain/zero/1.0/>. */
+
+package com.keylesspalace.tusky.util;
+
+import android.net.Uri;
+import android.support.annotation.Nullable;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class HttpHeaderLink {
+    private static class Parameter {
+        public String name;
+        public String value;
+    }
+
+    private List<Parameter> parameters;
+    public Uri uri;
+
+    private HttpHeaderLink(String uri) {
+        this.uri = Uri.parse(uri);
+        this.parameters = new ArrayList<>();
+    }
+
+    private static int findAny(String s, int fromIndex, char[] set) {
+        for (int i = fromIndex; i < s.length(); i++) {
+            char c = s.charAt(i);
+            for (char member : set) {
+                if (c == member) {
+                    return i;
+                }
+            }
+        }
+        return -1;
+    }
+
+    private static int findEndOfQuotedString(String line, int start) {
+        for (int i = start; i < line.length(); i++) {
+            char c = line.charAt(i);
+            if (c == '\\') {
+                i += 1;
+            } else if (c == '"') {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    private static class ValueResult {
+        String value;
+        int end;
+
+        ValueResult() {
+            end = -1;
+        }
+
+        void setValue(String value) {
+            value = value.trim();
+            if (!value.isEmpty()) {
+                this.value = value;
+            }
+        }
+    }
+
+    private static ValueResult parseValue(String line, int start) {
+        ValueResult result = new ValueResult();
+        int foundIndex = findAny(line, start, new char[] {';', ',', '"'});
+        if (foundIndex == -1) {
+            result.setValue(line.substring(start));
+            return result;
+        }
+        char c = line.charAt(foundIndex);
+        if (c == ';' || c == ',') {
+            result.end = foundIndex;
+            result.setValue(line.substring(start, foundIndex));
+            return result;
+        } else {
+            int quoteEnd = findEndOfQuotedString(line, foundIndex + 1);
+            if (quoteEnd == -1) {
+                quoteEnd = line.length();
+            }
+            result.end = quoteEnd;
+            result.setValue(line.substring(foundIndex + 1, quoteEnd));
+            return result;
+        }
+    }
+
+    private static int parseParameters(String line, int start, HttpHeaderLink link) {
+        for (int i = start; i < line.length(); i++) {
+            int foundIndex = findAny(line, i, new char[] {'=', ','});
+            if (foundIndex == -1) {
+                return -1;
+            } else if (line.charAt(foundIndex) == ',') {
+                return foundIndex;
+            }
+            Parameter parameter = new Parameter();
+            parameter.name = line.substring(line.indexOf(';', i) + 1, foundIndex).trim();
+            link.parameters.add(parameter);
+            ValueResult result = parseValue(line, foundIndex);
+            parameter.value = result.value;
+            if (result.end == -1) {
+                return -1;
+            } else {
+                i = result.end;
+            }
+        }
+        return -1;
+    }
+
+    public static List<HttpHeaderLink> parse(@Nullable String line) {
+        List<HttpHeaderLink> linkList = new ArrayList<>();
+        if (line != null) {
+            for (int i = 0; i < line.length(); i++) {
+                int uriEnd = line.indexOf('>', i);
+                String uri = line.substring(line.indexOf('<', i) + 1, uriEnd);
+                HttpHeaderLink link = new HttpHeaderLink(uri);
+                linkList.add(link);
+                int parseEnd = parseParameters(line, uriEnd, link);
+                if (parseEnd == -1) {
+                    break;
+                } else {
+                    i = parseEnd;
+                }
+            }
+        }
+        return linkList;
+    }
+
+    @Nullable
+    public static HttpHeaderLink findByRelationType(List<HttpHeaderLink> links,
+            String relationType) {
+        for (HttpHeaderLink link : links) {
+            for (Parameter parameter : link.parameters) {
+                if (parameter.name.equals("rel") && parameter.value.equals(relationType)) {
+                    return link;
+                }
+            }
+        }
+        return null;
+    }
+}