reftable: utility functions

This commit provides basic utility classes for the reftable library.

Signed-off-by: Han-Wen Nienhuys <[email protected]>
Helped-by: Johannes Schindelin <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: hanwen

Makefile

@@ -743,6 +743,7 @@ TEST_BUILTINS_OBJS += test-read-cache.o
 TEST_BUILTINS_OBJS += test-read-graph.o
 TEST_BUILTINS_OBJS += test-read-midx.o
 TEST_BUILTINS_OBJS += test-ref-store.o
+TEST_BUILTINS_OBJS += test-reftable.o
 TEST_BUILTINS_OBJS += test-regex.o
 TEST_BUILTINS_OBJS += test-repository.o
 TEST_BUILTINS_OBJS += test-revision-walking.o
@@ -821,6 +822,8 @@ TEST_SHELL_PATH = $(SHELL_PATH)
 
 LIB_FILE = libgit.a
 XDIFF_LIB = xdiff/lib.a
+REFTABLE_LIB = reftable/libreftable.a
+REFTABLE_TEST_LIB = reftable/libreftable_test.a
 
 GENERATED_H += command-list.h
 GENERATED_H += config-list.h
@@ -1195,7 +1198,7 @@ THIRD_PARTY_SOURCES += compat/regex/%
 THIRD_PARTY_SOURCES += sha1collisiondetection/%
 THIRD_PARTY_SOURCES += sha1dc/%
 
-GITLIBS = common-main.o $(LIB_FILE) $(XDIFF_LIB)
+GITLIBS = common-main.o $(LIB_FILE) $(XDIFF_LIB) $(REFTABLE_LIB)
 EXTLIBS =
 
 GIT_USER_AGENT = git/$(GIT_VERSION)
@@ -2446,7 +2449,15 @@ XDIFF_OBJS += xdiff/xutils.o
 .PHONY: xdiff-objs
 xdiff-objs: $(XDIFF_OBJS)
 
+REFTABLE_OBJS += reftable/basics.o
+REFTABLE_OBJS += reftable/error.o
+REFTABLE_OBJS += reftable/publicbasics.o
+
+REFTABLE_TEST_OBJS += reftable/test_framework.o
+REFTABLE_TEST_OBJS += reftable/basics_test.o
+
 TEST_OBJS := $(patsubst %$X,%.o,$(TEST_PROGRAMS)) $(patsubst %,t/helper/%,$(TEST_BUILTINS_OBJS))
+
 .PHONY: test-objs
 test-objs: $(TEST_OBJS)
 
@@ -2462,6 +2473,8 @@ OBJECTS += $(PROGRAM_OBJS)
 OBJECTS += $(TEST_OBJS)
 OBJECTS += $(XDIFF_OBJS)
 OBJECTS += $(FUZZ_OBJS)
+OBJECTS += $(REFTABLE_OBJS) $(REFTABLE_TEST_OBJS)
+
 ifndef NO_CURL
 	OBJECTS += http.o http-walker.o remote-curl.o
 endif
@@ -2612,6 +2625,12 @@ $(LIB_FILE): $(LIB_OBJS)
 $(XDIFF_LIB): $(XDIFF_OBJS)
 	$(QUIET_AR)$(AR) $(ARFLAGS) $@ $^
 
+$(REFTABLE_LIB): $(REFTABLE_OBJS)
+	$(QUIET_AR)$(RM) $@ && $(AR) $(ARFLAGS) $@ $^
+
+$(REFTABLE_TEST_LIB): $(REFTABLE_TEST_OBJS)
+	$(QUIET_AR)$(RM) $@ && $(AR) $(ARFLAGS) $@ $^
+
 export DEFAULT_EDITOR DEFAULT_PAGER
 
 Documentation/GIT-EXCLUDED-PROGRAMS: FORCE
@@ -2904,7 +2923,7 @@ perf: all
 
 t/helper/test-tool$X: $(patsubst %,t/helper/%,$(TEST_BUILTINS_OBJS))
 
-t/helper/test-%$X: t/helper/test-%.o GIT-LDFLAGS $(GITLIBS)
+t/helper/test-%$X: t/helper/test-%.o GIT-LDFLAGS $(GITLIBS) $(REFTABLE_TEST_LIB)
 	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) $(filter %.a,$^) $(LIBS)
 
 check-sha1:: t/helper/test-tool$X
@@ -3234,7 +3253,7 @@ cocciclean:
 clean: profile-clean coverage-clean cocciclean
 	$(RM) *.res
 	$(RM) $(OBJECTS)
-	$(RM) $(LIB_FILE) $(XDIFF_LIB)
+	$(RM) $(LIB_FILE) $(XDIFF_LIB) $(REFTABLE_LIB) $(REFTABLE_TEST_LIB)
 	$(RM) $(ALL_PROGRAMS) $(SCRIPT_LIB) $(BUILT_INS) git$X
 	$(RM) $(TEST_PROGRAMS)
 	$(RM) $(FUZZ_PROGRAMS)

contrib/buildsystems/CMakeLists.txt

@@ -640,6 +640,12 @@ parse_makefile_for_sources(libxdiff_SOURCES "XDIFF_OBJS")
 list(TRANSFORM libxdiff_SOURCES PREPEND "${CMAKE_SOURCE_DIR}/")
 add_library(xdiff STATIC ${libxdiff_SOURCES})
 
+#reftable
+parse_makefile_for_sources(reftable_SOURCES "REFTABLE_OBJS")
+
+list(TRANSFORM reftable_SOURCES PREPEND "${CMAKE_SOURCE_DIR}/")
+add_library(reftable STATIC ${reftable_SOURCES})
+
 if(WIN32)
 	if(NOT MSVC)#use windres when compiling with gcc and clang
 		add_custom_command(OUTPUT ${CMAKE_BINARY_DIR}/git.res
@@ -662,7 +668,7 @@ endif()
 #link all required libraries to common-main
 add_library(common-main OBJECT ${CMAKE_SOURCE_DIR}/common-main.c)
 
-target_link_libraries(common-main libgit xdiff ${ZLIB_LIBRARIES})
+target_link_libraries(common-main libgit xdiff reftable ${ZLIB_LIBRARIES})
 if(Intl_FOUND)
 	target_link_libraries(common-main ${Intl_LIBRARIES})
 endif()
@@ -902,11 +908,15 @@ if(BUILD_TESTING)
 add_executable(test-fake-ssh ${CMAKE_SOURCE_DIR}/t/helper/test-fake-ssh.c)
 target_link_libraries(test-fake-ssh common-main)
 
+#reftable-tests
+parse_makefile_for_sources(test-reftable_SOURCES "REFTABLE_TEST_OBJS")
+list(TRANSFORM test-reftable_SOURCES PREPEND "${CMAKE_SOURCE_DIR}/")
+
 #test-tool
 parse_makefile_for_sources(test-tool_SOURCES "TEST_BUILTINS_OBJS")
 
 list(TRANSFORM test-tool_SOURCES PREPEND "${CMAKE_SOURCE_DIR}/t/helper/")
-add_executable(test-tool ${CMAKE_SOURCE_DIR}/t/helper/test-tool.c ${test-tool_SOURCES})
+add_executable(test-tool ${CMAKE_SOURCE_DIR}/t/helper/test-tool.c ${test-tool_SOURCES} ${test-reftable_SOURCES})
 target_link_libraries(test-tool common-main)
 
 set_target_properties(test-fake-ssh test-tool

contrib/buildsystems/Generators/Vcxproj.pm

@@ -77,7 +77,7 @@ sub createProject {
     my $libs_release = "\n    ";
     my $libs_debug = "\n    ";
     if (!$static_library) {
-      $libs_release = join(";", sort(grep /^(?!libgit\.lib|xdiff\/lib\.lib|vcs-svn\/lib\.lib)/, @{$$build_structure{"$prefix${name}_LIBS"}}));
+      $libs_release = join(";", sort(grep /^(?!libgit\.lib|xdiff\/lib\.lib|vcs-svn\/lib\.lib|reftable\/libreftable\.lib)/, @{$$build_structure{"$prefix${name}_LIBS"}}));
       $libs_debug = $libs_release;
       $libs_debug =~ s/zlib\.lib/zlibd\.lib/g;
       $libs_debug =~ s/libexpat\.lib/libexpatd\.lib/g;
@@ -232,6 +232,7 @@ EOM
 EOM
     if (!$static_library || $target =~ 'vcs-svn' || $target =~ 'xdiff') {
       my $uuid_libgit = $$build_structure{"LIBS_libgit_GUID"};
+      my $uuid_libreftable = $$build_structure{"LIBS_reftable/libreftable_GUID"};
       my $uuid_xdiff_lib = $$build_structure{"LIBS_xdiff/lib_GUID"};
 
       print F << "EOM";
@@ -241,6 +242,14 @@ EOM
       <ReferenceOutputAssembly>false</ReferenceOutputAssembly>
     </ProjectReference>
 EOM
+      if (!($name =~ /xdiff|libreftable/)) {
+        print F << "EOM";
+    <ProjectReference Include="$cdup\\reftable\\libreftable\\libreftable.vcxproj">
+      <Project>$uuid_libreftable</Project>
+      <ReferenceOutputAssembly>false</ReferenceOutputAssembly>
+    </ProjectReference>
+EOM
+      }
       if (!($name =~ 'xdiff')) {
         print F << "EOM";
     <ProjectReference Include="$cdup\\xdiff\\lib\\xdiff_lib.vcxproj">

reftable/basics.c

@@ -0,0 +1,128 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "basics.h"
+
+void put_be24(uint8_t *out, uint32_t i)
+{
+	out[0] = (uint8_t)((i >> 16) & 0xff);
+	out[1] = (uint8_t)((i >> 8) & 0xff);
+	out[2] = (uint8_t)(i & 0xff);
+}
+
+uint32_t get_be24(uint8_t *in)
+{
+	return (uint32_t)(in[0]) << 16 | (uint32_t)(in[1]) << 8 |
+	       (uint32_t)(in[2]);
+}
+
+void put_be16(uint8_t *out, uint16_t i)
+{
+	out[0] = (uint8_t)((i >> 8) & 0xff);
+	out[1] = (uint8_t)(i & 0xff);
+}
+
+int binsearch(size_t sz, int (*f)(size_t k, void *args), void *args)
+{
+	size_t lo = 0;
+	size_t hi = sz;
+
+	/* Invariants:
+	 *
+	 *  (hi == sz) || f(hi) == true
+	 *  (lo == 0 && f(0) == true) || fi(lo) == false
+	 */
+	while (hi - lo > 1) {
+		size_t mid = lo + (hi - lo) / 2;
+
+		if (f(mid, args))
+			hi = mid;
+		else
+			lo = mid;
+	}
+
+	if (lo)
+		return hi;
+
+	return f(0, args) ? 0 : 1;
+}
+
+void free_names(char **a)
+{
+	char **p;
+	if (!a) {
+		return;
+	}
+	for (p = a; *p; p++) {
+		reftable_free(*p);
+	}
+	reftable_free(a);
+}
+
+int names_length(char **names)
+{
+	char **p = names;
+	for (; *p; p++) {
+		/* empty */
+	}
+	return p - names;
+}
+
+void parse_names(char *buf, int size, char ***namesp)
+{
+	char **names = NULL;
+	size_t names_cap = 0;
+	size_t names_len = 0;
+
+	char *p = buf;
+	char *end = buf + size;
+	while (p < end) {
+		char *next = strchr(p, '\n');
+		if (next && next < end) {
+			*next = 0;
+		} else {
+			next = end;
+		}
+		if (p < next) {
+			if (names_len == names_cap) {
+				names_cap = 2 * names_cap + 1;
+				names = reftable_realloc(
+					names, names_cap * sizeof(*names));
+			}
+			names[names_len++] = xstrdup(p);
+		}
+		p = next + 1;
+	}
+
+	names = reftable_realloc(names, (names_len + 1) * sizeof(*names));
+	names[names_len] = NULL;
+	*namesp = names;
+}
+
+int names_equal(char **a, char **b)
+{
+	int i = 0;
+	for (; a[i] && b[i]; i++) {
+		if (strcmp(a[i], b[i])) {
+			return 0;
+		}
+	}
+
+	return a[i] == b[i];
+}
+
+int common_prefix_size(struct strbuf *a, struct strbuf *b)
+{
+	int p = 0;
+	for (; p < a->len && p < b->len; p++) {
+		if (a->buf[p] != b->buf[p])
+			break;
+	}
+
+	return p;
+}

reftable/basics.h

@@ -0,0 +1,60 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#ifndef BASICS_H
+#define BASICS_H
+
+/*
+ * miscellaneous utilities that are not provided by Git.
+ */
+
+#include "system.h"
+
+/* Bigendian en/decoding of integers */
+
+void put_be24(uint8_t *out, uint32_t i);
+uint32_t get_be24(uint8_t *in);
+void put_be16(uint8_t *out, uint16_t i);
+
+/*
+ * find smallest index i in [0, sz) at which f(i) is true, assuming
+ * that f is ascending. Return sz if f(i) is false for all indices.
+ *
+ * Contrary to bsearch(3), this returns something useful if the argument is not
+ * found.
+ */
+int binsearch(size_t sz, int (*f)(size_t k, void *args), void *args);
+
+/*
+ * Frees a NULL terminated array of malloced strings. The array itself is also
+ * freed.
+ */
+void free_names(char **a);
+
+/* parse a newline separated list of names. `size` is the length of the buffer,
+ * without terminating '\0'. Empty names are discarded. */
+void parse_names(char *buf, int size, char ***namesp);
+
+/* compares two NULL-terminated arrays of strings. */
+int names_equal(char **a, char **b);
+
+/* returns the array size of a NULL-terminated array of strings. */
+int names_length(char **names);
+
+/* Allocation routines; they invoke the functions set through
+ * reftable_set_alloc() */
+void *reftable_malloc(size_t sz);
+void *reftable_realloc(void *p, size_t sz);
+void reftable_free(void *p);
+void *reftable_calloc(size_t sz);
+
+/* Find the longest shared prefix size of `a` and `b` */
+struct strbuf;
+int common_prefix_size(struct strbuf *a, struct strbuf *b);
+
+#endif