config: Add an option to deduplicate entries

Closes: #224

src/clipmenud.c

@@ -218,7 +218,9 @@ static uint64_t store_clip(char *text) {
         dbg("Possible partial of last clip, replacing\n");
         expect(cs_replace(&cs, CS_ITER_NEWEST_FIRST, 0, text, &hash) == 0);
     } else {
-        expect(cs_add(&cs, text, &hash) == 0);
+        expect(cs_add(&cs, text, &hash,
+                      cfg.deduplicate ? CS_DUPE_KEEP_LAST : CS_DUPE_KEEP_ALL) ==
+               0);
     }
 
     if (last_text) {

src/config.c

@@ -269,6 +269,8 @@ int config_setup_internal(FILE *file, struct config *cfg) {
         {"max_clips_batch", "CM_MAX_CLIPS_BATCH", &cfg->max_clips_batch,
          convert_positive_int, "100", 0},
         {"oneshot", "CM_ONESHOT", &cfg->oneshot, convert_positive_int, "0", 0},
+        {"deduplicate", "CM_DEDUPLICATE", &cfg->deduplicate, convert_bool, "0",
+         0},
         {"own_clipboard", "CM_OWN_CLIPBOARD", &cfg->own_clipboard, convert_bool,
          "0", 0},
         {"selections", "CM_SELECTIONS", &cfg->selections, convert_selections,

src/config.h

@@ -43,6 +43,7 @@ struct config {
     int max_clips;
     int max_clips_batch;
     int oneshot;
+    bool deduplicate;
     bool own_clipboard;
     struct selection *owned_selections;
     struct selection *selections;

src/store.c

@@ -527,28 +527,53 @@ int cs_content_get(struct clip_store *cs, uint64_t hash,
     return 0;
 }
 
+/**
+ * Move the entry with the specified hash to the newest slot.
+ *
+ * @cs: The clip store to operate on
+ * @hash: The hash of the entry to move
+ */
+static int cs_make_newest(struct clip_store *cs, uint64_t hash) {
+    _drop_(cs_unref) struct ref_guard guard = cs_ref(cs);
+    if (guard.status < 0) {
+        return guard.status;
+    }
+
+    for (int i = 0; i < (int)cs->local_nr_snips; ++i) {
+        if (cs->snips[i].hash == hash) {
+            struct cs_snip tmp = cs->snips[i];
+            memmove(cs->snips + i, cs->snips + i + 1,
+                    (cs->local_nr_snips - (i + 1)) * sizeof(*cs->snips));
+            cs->snips[cs->local_nr_snips - 1] = tmp;
+            return 0;
+        }
+    }
+    die("unreachable");
+}
+
 /**
  * Add a new content entry to the clip store and content directory.
  *
  * @cs: The clip store to operate on
  * @content: The content to add
  * @out_hash: Output for the generated hash, or NULL
+ * @dupe_policy: Policy to use for duplicate entries
  */
-int cs_add(struct clip_store *cs, const char *content, uint64_t *out_hash) {
+int cs_add(struct clip_store *cs, const char *content, uint64_t *out_hash,
+           enum cs_dupe_policy dupe_policy) {
     uint64_t hash = djb64_hash(content);
     char line[CS_SNIP_LINE_SIZE];
     size_t nr_lines = first_line(content, line);
 
-    int ret = cs_content_add(cs, hash, content, CS_DUPE_KEEP_ALL);
-    if (ret < 0) {
-        return ret;
-    }
-
     if (out_hash) {
         *out_hash = hash;
     }
 
-    return cs_snip_add(cs, hash, line, nr_lines);
+    int ret = cs_content_add(cs, hash, content, dupe_policy);
+    if (ret == -EEXIST && dupe_policy == CS_DUPE_KEEP_LAST) {
+        return cs_make_newest(cs, hash);
+    }
+    return ret ? ret : cs_snip_add(cs, hash, line, nr_lines);
 }
 
 /**

src/store.h

@@ -166,7 +166,8 @@ void drop_cs_destroy(struct clip_store *cs);
 int _must_use_ _nonnull_ cs_content_get(struct clip_store *cs, uint64_t hash,
                                         struct cs_content *content);
 int _must_use_ _nonnull_n_(1)
-    cs_add(struct clip_store *cs, const char *content, uint64_t *out_hash);
+    cs_add(struct clip_store *cs, const char *content, uint64_t *out_hash,
+           enum cs_dupe_policy dupe_policy);
 bool _must_use_ _nonnull_ cs_snip_iter(struct ref_guard *guard,
                                        enum cs_iter_direction direction,
                                        struct cs_snip **snip);