Adding upstream version 1:2.30.2.upstream/1%2.30.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 362 insertions, 0 deletions

diff --git a/fsmonitor.c b/fsmonitor.c
new file mode 100644
index 0000000..ca031c3
--- /dev/null
+++ b/fsmonitor.c
@@ -0,0 +1,362 @@
+#include "cache.h"
+#include "config.h"
+#include "dir.h"
+#include "ewah/ewok.h"
+#include "fsmonitor.h"
+#include "run-command.h"
+#include "strbuf.h"
+
+#define INDEX_EXTENSION_VERSION1	(1)
+#define INDEX_EXTENSION_VERSION2	(2)
+#define HOOK_INTERFACE_VERSION1		(1)
+#define HOOK_INTERFACE_VERSION2		(2)
+
+struct trace_key trace_fsmonitor = TRACE_KEY_INIT(FSMONITOR);
+
+static void fsmonitor_ewah_callback(size_t pos, void *is)
+{
+	struct index_state *istate = (struct index_state *)is;
+	struct cache_entry *ce;
+
+	if (pos >= istate->cache_nr)
+		BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" >= %u)",
+		    (uintmax_t)pos, istate->cache_nr);
+
+	ce = istate->cache[pos];
+	ce->ce_flags &= ~CE_FSMONITOR_VALID;
+}
+
+static int fsmonitor_hook_version(void)
+{
+	int hook_version;
+
+	if (git_config_get_int("core.fsmonitorhookversion", &hook_version))
+		return -1;
+
+	if (hook_version == HOOK_INTERFACE_VERSION1 ||
+	    hook_version == HOOK_INTERFACE_VERSION2)
+		return hook_version;
+
+	warning("Invalid hook version '%i' in core.fsmonitorhookversion. "
+		"Must be 1 or 2.", hook_version);
+	return -1;
+}
+
+int read_fsmonitor_extension(struct index_state *istate, const void *data,
+	unsigned long sz)
+{
+	const char *index = data;
+	uint32_t hdr_version;
+	uint32_t ewah_size;
+	struct ewah_bitmap *fsmonitor_dirty;
+	int ret;
+	uint64_t timestamp;
+	struct strbuf last_update = STRBUF_INIT;
+
+	if (sz < sizeof(uint32_t) + 1 + sizeof(uint32_t))
+		return error("corrupt fsmonitor extension (too short)");
+
+	hdr_version = get_be32(index);
+	index += sizeof(uint32_t);
+	if (hdr_version == INDEX_EXTENSION_VERSION1) {
+		timestamp = get_be64(index);
+		strbuf_addf(&last_update, "%"PRIu64"", timestamp);
+		index += sizeof(uint64_t);
+	} else if (hdr_version == INDEX_EXTENSION_VERSION2) {
+		strbuf_addstr(&last_update, index);
+		index += last_update.len + 1;
+	} else {
+		return error("bad fsmonitor version %d", hdr_version);
+	}
+
+	istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL);
+
+	ewah_size = get_be32(index);
+	index += sizeof(uint32_t);
+
+	fsmonitor_dirty = ewah_new();
+	ret = ewah_read_mmap(fsmonitor_dirty, index, ewah_size);
+	if (ret != ewah_size) {
+		ewah_free(fsmonitor_dirty);
+		return error("failed to parse ewah bitmap reading fsmonitor index extension");
+	}
+	istate->fsmonitor_dirty = fsmonitor_dirty;
+
+	if (!istate->split_index &&
+	    istate->fsmonitor_dirty->bit_size > istate->cache_nr)
+		BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)",
+		    (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr);
+
+	trace_printf_key(&trace_fsmonitor, "read fsmonitor extension successful");
+	return 0;
+}
+
+void fill_fsmonitor_bitmap(struct index_state *istate)
+{
+	unsigned int i, skipped = 0;
+	istate->fsmonitor_dirty = ewah_new();
+	for (i = 0; i < istate->cache_nr; i++) {
+		if (istate->cache[i]->ce_flags & CE_REMOVE)
+			skipped++;
+		else if (!(istate->cache[i]->ce_flags & CE_FSMONITOR_VALID))
+			ewah_set(istate->fsmonitor_dirty, i - skipped);
+	}
+}
+
+void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate)
+{
+	uint32_t hdr_version;
+	uint32_t ewah_start;
+	uint32_t ewah_size = 0;
+	int fixup = 0;
+
+	if (!istate->split_index &&
+	    istate->fsmonitor_dirty->bit_size > istate->cache_nr)
+		BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)",
+		    (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr);
+
+	put_be32(&hdr_version, INDEX_EXTENSION_VERSION2);
+	strbuf_add(sb, &hdr_version, sizeof(uint32_t));
+
+	strbuf_addstr(sb, istate->fsmonitor_last_update);
+	strbuf_addch(sb, 0); /* Want to keep a NUL */
+
+	fixup = sb->len;
+	strbuf_add(sb, &ewah_size, sizeof(uint32_t)); /* we'll fix this up later */
+
+	ewah_start = sb->len;
+	ewah_serialize_strbuf(istate->fsmonitor_dirty, sb);
+	ewah_free(istate->fsmonitor_dirty);
+	istate->fsmonitor_dirty = NULL;
+
+	/* fix up size field */
+	put_be32(&ewah_size, sb->len - ewah_start);
+	memcpy(sb->buf + fixup, &ewah_size, sizeof(uint32_t));
+
+	trace_printf_key(&trace_fsmonitor, "write fsmonitor extension successful");
+}
+
+/*
+ * Call the query-fsmonitor hook passing the last update token of the saved results.
+ */
+static int query_fsmonitor(int version, const char *last_update, struct strbuf *query_result)
+{
+	struct child_process cp = CHILD_PROCESS_INIT;
+
+	if (!core_fsmonitor)
+		return -1;
+
+	strvec_push(&cp.args, core_fsmonitor);
+	strvec_pushf(&cp.args, "%d", version);
+	strvec_pushf(&cp.args, "%s", last_update);
+	cp.use_shell = 1;
+	cp.dir = get_git_work_tree();
+
+	return capture_command(&cp, query_result, 1024);
+}
+
+static void fsmonitor_refresh_callback(struct index_state *istate, const char *name)
+{
+	int pos = index_name_pos(istate, name, strlen(name));
+
+	if (pos >= 0) {
+		struct cache_entry *ce = istate->cache[pos];
+		ce->ce_flags &= ~CE_FSMONITOR_VALID;
+	}
+
+	/*
+	 * Mark the untracked cache dirty even if it wasn't found in the index
+	 * as it could be a new untracked file.
+	 */
+	trace_printf_key(&trace_fsmonitor, "fsmonitor_refresh_callback '%s'", name);
+	untracked_cache_invalidate_path(istate, name, 0);
+}
+
+void refresh_fsmonitor(struct index_state *istate)
+{
+	struct strbuf query_result = STRBUF_INIT;
+	int query_success = 0, hook_version = -1;
+	size_t bol = 0; /* beginning of line */
+	uint64_t last_update;
+	struct strbuf last_update_token = STRBUF_INIT;
+	char *buf;
+	unsigned int i;
+
+	if (!core_fsmonitor || istate->fsmonitor_has_run_once)
+		return;
+
+	hook_version = fsmonitor_hook_version();
+
+	istate->fsmonitor_has_run_once = 1;
+
+	trace_printf_key(&trace_fsmonitor, "refresh fsmonitor");
+	/*
+	 * This could be racy so save the date/time now and query_fsmonitor
+	 * should be inclusive to ensure we don't miss potential changes.
+	 */
+	last_update = getnanotime();
+	if (hook_version == HOOK_INTERFACE_VERSION1)
+		strbuf_addf(&last_update_token, "%"PRIu64"", last_update);
+
+	/*
+	 * If we have a last update token, call query_fsmonitor for the set of
+	 * changes since that token, else assume everything is possibly dirty
+	 * and check it all.
+	 */
+	if (istate->fsmonitor_last_update) {
+		if (hook_version == -1 || hook_version == HOOK_INTERFACE_VERSION2) {
+			query_success = !query_fsmonitor(HOOK_INTERFACE_VERSION2,
+				istate->fsmonitor_last_update, &query_result);
+
+			if (query_success) {
+				if (hook_version < 0)
+					hook_version = HOOK_INTERFACE_VERSION2;
+
+				/*
+				 * First entry will be the last update token
+				 * Need to use a char * variable because static
+				 * analysis was suggesting to use strbuf_addbuf
+				 * but we don't want to copy the entire strbuf
+				 * only the chars up to the first NUL
+				 */
+				buf = query_result.buf;
+				strbuf_addstr(&last_update_token, buf);
+				if (!last_update_token.len) {
+					warning("Empty last update token.");
+					query_success = 0;
+				} else {
+					bol = last_update_token.len + 1;
+				}
+			} else if (hook_version < 0) {
+				hook_version = HOOK_INTERFACE_VERSION1;
+				if (!last_update_token.len)
+					strbuf_addf(&last_update_token, "%"PRIu64"", last_update);
+			}
+		}
+
+		if (hook_version == HOOK_INTERFACE_VERSION1) {
+			query_success = !query_fsmonitor(HOOK_INTERFACE_VERSION1,
+				istate->fsmonitor_last_update, &query_result);
+		}
+
+		trace_performance_since(last_update, "fsmonitor process '%s'", core_fsmonitor);
+		trace_printf_key(&trace_fsmonitor, "fsmonitor process '%s' returned %s",
+			core_fsmonitor, query_success ? "success" : "failure");
+	}
+
+	/* a fsmonitor process can return '/' to indicate all entries are invalid */
+	if (query_success && query_result.buf[bol] != '/') {
+		/* Mark all entries returned by the monitor as dirty */
+		buf = query_result.buf;
+		for (i = bol; i < query_result.len; i++) {
+			if (buf[i] != '\0')
+				continue;
+			fsmonitor_refresh_callback(istate, buf + bol);
+			bol = i + 1;
+		}
+		if (bol < query_result.len)
+			fsmonitor_refresh_callback(istate, buf + bol);
+
+		/* Now mark the untracked cache for fsmonitor usage */
+		if (istate->untracked)
+			istate->untracked->use_fsmonitor = 1;
+	} else {
+
+		/* We only want to run the post index changed hook if we've actually changed entries, so keep track
+		 * if we actually changed entries or not */
+		int is_cache_changed = 0;
+		/* Mark all entries invalid */
+		for (i = 0; i < istate->cache_nr; i++) {
+			if (istate->cache[i]->ce_flags & CE_FSMONITOR_VALID) {
+				is_cache_changed = 1;
+				istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
+			}
+		}
+
+		/* If we're going to check every file, ensure we save the results */
+		if (is_cache_changed)
+			istate->cache_changed |= FSMONITOR_CHANGED;
+
+		if (istate->untracked)
+			istate->untracked->use_fsmonitor = 0;
+	}
+	strbuf_release(&query_result);
+
+	/* Now that we've updated istate, save the last_update_token */
+	FREE_AND_NULL(istate->fsmonitor_last_update);
+	istate->fsmonitor_last_update = strbuf_detach(&last_update_token, NULL);
+}
+
+void add_fsmonitor(struct index_state *istate)
+{
+	unsigned int i;
+	struct strbuf last_update = STRBUF_INIT;
+
+	if (!istate->fsmonitor_last_update) {
+		trace_printf_key(&trace_fsmonitor, "add fsmonitor");
+		istate->cache_changed |= FSMONITOR_CHANGED;
+		strbuf_addf(&last_update, "%"PRIu64"", getnanotime());
+		istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL);
+
+		/* reset the fsmonitor state */
+		for (i = 0; i < istate->cache_nr; i++)
+			istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
+
+		/* reset the untracked cache */
+		if (istate->untracked) {
+			add_untracked_cache(istate);
+			istate->untracked->use_fsmonitor = 1;
+		}
+
+		/* Update the fsmonitor state */
+		refresh_fsmonitor(istate);
+	}
+}
+
+void remove_fsmonitor(struct index_state *istate)
+{
+	if (istate->fsmonitor_last_update) {
+		trace_printf_key(&trace_fsmonitor, "remove fsmonitor");
+		istate->cache_changed |= FSMONITOR_CHANGED;
+		FREE_AND_NULL(istate->fsmonitor_last_update);
+	}
+}
+
+void tweak_fsmonitor(struct index_state *istate)
+{
+	unsigned int i;
+	int fsmonitor_enabled = git_config_get_fsmonitor();
+
+	if (istate->fsmonitor_dirty) {
+		if (fsmonitor_enabled) {
+			/* Mark all entries valid */
+			for (i = 0; i < istate->cache_nr; i++) {
+				istate->cache[i]->ce_flags |= CE_FSMONITOR_VALID;
+			}
+
+			/* Mark all previously saved entries as dirty */
+			if (istate->fsmonitor_dirty->bit_size > istate->cache_nr)
+				BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)",
+				    (uintmax_t)istate->fsmonitor_dirty->bit_size, istate->cache_nr);
+			ewah_each_bit(istate->fsmonitor_dirty, fsmonitor_ewah_callback, istate);
+
+			refresh_fsmonitor(istate);
+		}
+
+		ewah_free(istate->fsmonitor_dirty);
+		istate->fsmonitor_dirty = NULL;
+	}
+
+	switch (fsmonitor_enabled) {
+	case -1: /* keep: do nothing */
+		break;
+	case 0: /* false */
+		remove_fsmonitor(istate);
+		break;
+	case 1: /* true */
+		add_fsmonitor(istate);
+		break;
+	default: /* unknown value: do nothing */
+		break;
+	}
+}