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-rw-r--r--statinfo.h89
1 files changed, 89 insertions, 0 deletions
diff --git a/statinfo.h b/statinfo.h
new file mode 100644
index 0000000..700f502
--- /dev/null
+++ b/statinfo.h
@@ -0,0 +1,89 @@
+#ifndef STATINFO_H
+#define STATINFO_H
+
+struct index_state;
+
+/*
+ * The "cache_time" is just the low 32 bits of the
+ * time. It doesn't matter if it overflows - we only
+ * check it for equality in the 32 bits we save.
+ */
+struct cache_time {
+ uint32_t sec;
+ uint32_t nsec;
+};
+
+struct stat_data {
+ struct cache_time sd_ctime;
+ struct cache_time sd_mtime;
+ unsigned int sd_dev;
+ unsigned int sd_ino;
+ unsigned int sd_uid;
+ unsigned int sd_gid;
+ unsigned int sd_size;
+};
+
+/*
+ * A struct to encapsulate the concept of whether a file has changed
+ * since we last checked it. This uses criteria similar to those used
+ * for the index.
+ */
+struct stat_validity {
+ struct stat_data *sd;
+};
+
+#define MTIME_CHANGED 0x0001
+#define CTIME_CHANGED 0x0002
+#define OWNER_CHANGED 0x0004
+#define MODE_CHANGED 0x0008
+#define INODE_CHANGED 0x0010
+#define DATA_CHANGED 0x0020
+#define TYPE_CHANGED 0x0040
+
+/*
+ * Record to sd the data from st that we use to check whether a file
+ * might have changed.
+ */
+void fill_stat_data(struct stat_data *sd, struct stat *st);
+
+/*
+ * Return 0 if st is consistent with a file not having been changed
+ * since sd was filled. If there are differences, return a
+ * combination of MTIME_CHANGED, CTIME_CHANGED, OWNER_CHANGED,
+ * INODE_CHANGED, and DATA_CHANGED.
+ */
+int match_stat_data(const struct stat_data *sd, struct stat *st);
+
+void stat_validity_clear(struct stat_validity *sv);
+
+/*
+ * Returns 1 if the path is a regular file (or a symlink to a regular
+ * file) and matches the saved stat_validity, 0 otherwise. A missing
+ * or inaccessible file is considered a match if the struct was just
+ * initialized, or if the previous update found an inaccessible file.
+ */
+int stat_validity_check(struct stat_validity *sv, const char *path);
+
+/*
+ * Update the stat_validity from a file opened at descriptor fd. If
+ * the file is missing, inaccessible, or not a regular file, then
+ * future calls to stat_validity_check will match iff one of those
+ * conditions continues to be true.
+ */
+void stat_validity_update(struct stat_validity *sv, int fd);
+
+#if defined(DT_UNKNOWN) && !defined(NO_D_TYPE_IN_DIRENT)
+#define DTYPE(de) ((de)->d_type)
+#else
+#undef DT_UNKNOWN
+#undef DT_DIR
+#undef DT_REG
+#undef DT_LNK
+#define DT_UNKNOWN 0
+#define DT_DIR 1
+#define DT_REG 2
+#define DT_LNK 3
+#define DTYPE(de) DT_UNKNOWN
+#endif
+
+#endif