Merge branch 'ds/sparse-cone'

Management of sparsely checked-out working tree has gained a
dedicated "sparse-checkout" command.

* ds/sparse-cone: (21 commits)
  sparse-checkout: improve OS ls compatibility
  sparse-checkout: respect core.ignoreCase in cone mode
  sparse-checkout: check for dirty status
  sparse-checkout: update working directory in-process for 'init'
  sparse-checkout: cone mode should not interact with .gitignore
  sparse-checkout: write using lockfile
  sparse-checkout: use in-process update for disable subcommand
  sparse-checkout: update working directory in-process
  sparse-checkout: sanitize for nested folders
  unpack-trees: add progress to clear_ce_flags()
  unpack-trees: hash less in cone mode
  sparse-checkout: init and set in cone mode
  sparse-checkout: use hashmaps for cone patterns
  sparse-checkout: add 'cone' mode
  trace2: add region in clear_ce_flags
  sparse-checkout: create 'disable' subcommand
  sparse-checkout: add '--stdin' option to set subcommand
  sparse-checkout: 'set' subcommand
  clone: add --sparse mode
  sparse-checkout: create 'init' subcommand
  ...

dir.h

@@ -2,6 +2,7 @@
 #define DIR_H
 
 #include "cache.h"
+#include "hashmap.h"
 #include "strbuf.h"
 
 /**
@@ -70,6 +71,13 @@ struct path_pattern {
 	int srcpos;
 };
 
+/* used for hashmaps for cone patterns */
+struct pattern_entry {
+	struct hashmap_entry ent;
+	char *pattern;
+	size_t patternlen;
+};
+
 /*
  * Each excludes file will be parsed into a fresh exclude_list which
  * is appended to the relevant exclude_list_group (either EXC_DIRS or
@@ -88,6 +96,26 @@ struct pattern_list {
 	const char *src;
 
 	struct path_pattern **patterns;
+
+	/*
+	 * While scanning the excludes, we attempt to match the patterns
+	 * with a more restricted set that allows us to use hashsets for
+	 * matching logic, which is faster than the linear lookup in the
+	 * excludes array above. If non-zero, that check succeeded.
+	 */
+	unsigned use_cone_patterns;
+	unsigned full_cone;
+
+	/*
+	 * Stores paths where everything starting with those paths
+	 * is included.
+	 */
+	struct hashmap recursive_hashmap;
+
+	/*
+	 * Used to check single-level parents of blobs.
+	 */
+	struct hashmap parent_hashmap;
 };
 
 /*
@@ -345,6 +373,7 @@ enum pattern_match_result {
 	UNDECIDED = -1,
 	NOT_MATCHED = 0,
 	MATCHED = 1,
+	MATCHED_RECURSIVE = 2,
 };
 
 /*
@@ -380,6 +409,13 @@ int is_excluded(struct dir_struct *dir,
 		struct index_state *istate,
 		const char *name, int *dtype);
 
+int pl_hashmap_cmp(const void *unused_cmp_data,
+		   const struct hashmap_entry *a,
+		   const struct hashmap_entry *b,
+		   const void *key);
+int hashmap_contains_parent(struct hashmap *map,
+			    const char *path,
+			    struct strbuf *buffer);
 struct pattern_list *add_pattern_list(struct dir_struct *dir,
 				      int group_type, const char *src);
 int add_patterns_from_file_to_list(const char *fname, const char *base, int baselen,