1 files changed, 82 insertions, 0 deletions
diff --git a/src/lib-storage/index/index-thread-private.h b/src/lib-storage/index/index-thread-private.h
new file mode 100644
index 0000000..ed2837b
--- /dev/null
+++ b/src/lib-storage/index/index-thread-private.h
@@ -0,0 +1,82 @@
+#ifndef INDEX_THREAD_PRIVATE_H
+#define INDEX_THREAD_PRIVATE_H
+
+#include "crc32.h"
+#include "mail-thread.h"
+#include "mail-index-strmap.h"
+
+#define MAIL_THREAD_INDEX_SUFFIX ".thread"
+
+/* After initially building the index, assign first_invalid_msgid_idx to
+   the next unused index + SKIP_COUNT. When more messages are added and
+   the next valid msgid conflicts with the first invalid msgid, the invalid
+   msgids will be moved forward again this many indexes. */
+#define THREAD_INVALID_MSGID_STR_IDX_SKIP_COUNT \
+	(4096 / sizeof(struct mail_thread_node))
+
+#define HDR_MESSAGE_ID "message-id"
+#define HDR_IN_REPLY_TO "in-reply-to"
+#define HDR_REFERENCES "references"
+#define HDR_SUBJECT "subject"
+
+#define MAIL_THREAD_NODE_REF_MSGID 0
+#define MAIL_THREAD_NODE_REF_INREPLYTO 1
+#define MAIL_THREAD_NODE_REF_REFERENCES1 2
+
+struct mail_thread_node {
+	/* UID of the message, or 0 for dummy nodes */
+	uint32_t uid;
+	/* Index for this node's parent node, 0 = this is root */
+	uint32_t parent_idx;
+	/* Number of messages containing "this message" -> "parent message"
+	   link, i.e. "number of links to parent node". However since parents
+	   can change, not all of these references might be from our current
+	   child nodes. When this refcount reaches 0, it means we must detach
+	   from our parent. */
+	unsigned int parent_link_refcount:30;
+	/* If uid is expunged, rebuild the thread tree. */
+	bool expunge_rebuilds:1;
+	/* If a link between this node and its child gets unreferenced,
+	   rebuild the thread tree. */
+	bool child_unref_rebuilds:1;
+};
+ARRAY_DEFINE_TYPE(mail_thread_node, struct mail_thread_node);
+#define MAIL_THREAD_NODE_EXISTS(node) \
+	((node)->uid != 0)
+
+struct mail_thread_cache {
+	uint32_t last_uid;
+	/* indexes used for invalid Message-IDs. that means no other messages
+	   point to them and they can safely be moved around whenever
+	   necessary. */
+	uint32_t first_invalid_msgid_str_idx;
+	uint32_t next_invalid_msgid_str_idx;
+
+	struct mail_search_result *search_result;
+
+	/* indexed by mail_index_strmap_rec.str_idx */
+	ARRAY_TYPE(mail_thread_node) thread_nodes;
+};
+
+static inline uint32_t crc32_str_nonzero(const char *str)
+{
+	uint32_t value = crc32_str(str);
+	return value == 0 ? 1 : value;
+}
+
+void mail_thread_add(struct mail_thread_cache *cache,
+		     const struct mail_index_strmap_rec *msgid_map,
+		     unsigned int *msgid_map_idx);
+bool mail_thread_remove(struct mail_thread_cache *cache,
+			const struct mail_index_strmap_rec *msgid_map,
+			unsigned int *msgid_map_idx);
+
+struct mail_thread_iterate_context *
+mail_thread_iterate_init_full(struct mail_thread_cache *cache,
+			      struct mail *tmp_mail,
+			      enum mail_thread_type thread_type,
+			      bool return_seqs);
+
+void index_thread_mailbox_opened(struct mailbox *box);
+
+#endif