From: Stefan Xenos <sxenos@xxxxxxxxxx>
This patch adds the get_metacommit_content method, which can classify
commits as either metacommits or normal commits, determine whether they
are abandoned, and extract the content commit's object id from the
metacommit.
Signed-off-by: Stefan Xenos <sxenos@xxxxxxxxxx>
---
Makefile | 1 +
metacommit-parser.c | 110 ++++++++++++++++++++++++++++++++++++++++++++
metacommit-parser.h | 16 +++++++
3 files changed, 127 insertions(+)
create mode 100644 metacommit-parser.c
create mode 100644 metacommit-parser.h
diff --git a/Makefile b/Makefile
index f0b2299172..ab1103a9e9 100644
--- a/Makefile
+++ b/Makefile
@@ -939,6 +939,7 @@ LIB_OBJS += merge.o
LIB_OBJS += merge-blobs.o
LIB_OBJS += merge-recursive.o
LIB_OBJS += mergesort.o
+LIB_OBJS += metacommit-parser.o
LIB_OBJS += midx.o
LIB_OBJS += name-hash.o
LIB_OBJS += negotiator/default.o
diff --git a/metacommit-parser.c b/metacommit-parser.c
new file mode 100644
index 0000000000..70c1428bfc
--- /dev/null
+++ b/metacommit-parser.c
@@ -0,0 +1,110 @@
+#include "cache.h"
+#include "metacommit-parser.h"
+#include "commit.h"
+
+/*
+ * Search the commit buffer for a line starting with the given key. Unlike
+ * find_commit_header, this also searches the commit message body.
+ */
+static const char *find_key(const char *msg, const char *key, size_t *out_len)
+{
+ int key_len = strlen(key);
+ const char *line = msg;
+
+ while (line) {
+ const char *eol = strchrnul(line, '\n');
+
+ if (eol - line > key_len && !memcmp(line, key, key_len) &&
+ line[key_len] == ' ') {
+ *out_len = eol - line - key_len - 1;
+ return line + key_len + 1;
+ }
+ line = *eol ? eol + 1 : NULL;
+ }
+ return NULL;
+}
+
+static struct commit *get_commit_by_index(struct commit_list *to_search, int index)
+{
+ while (to_search && index) {
+ to_search = to_search->next;
+ index--;
+ }
+
+ if (!to_search)
+ return NULL;
+
+ return to_search->item;
+}
+
+/*
+ * Writes the index of the content parent to "result". Returns the metacommit
+ * type. See the METACOMMIT_TYPE_* constants.
+ */
+static int index_of_content_commit(const char *buffer, int *result)
+{
+ int index = 0;
+ int ret = METACOMMIT_TYPE_NONE;
+ size_t parent_types_size;
+ const char *parent_types = find_key(buffer, "parent-type",
+ &parent_types_size);
+ const char *end;
+ const char *enum_start = parent_types;
+ int enum_length = 0;
+
+ if (!parent_types)
+ return METACOMMIT_TYPE_NONE;
+
+ end = &parent_types[parent_types_size];
+
+ while (1) {
+ char next = *parent_types;
+ if (next == ' ' || parent_types >= end) {
+ if (enum_length == 1) {
+ char first_char_in_enum = *enum_start;
+ if (first_char_in_enum == 'c') {
+ ret = METACOMMIT_TYPE_NORMAL;
+ break;
+ }
+ if (first_char_in_enum == 'a') {
+ ret = METACOMMIT_TYPE_ABANDONED;
+ break;
+ }
+ }
+ if (parent_types >= end)
+ return METACOMMIT_TYPE_NONE;
+ enum_start = parent_types + 1;
+ enum_length = 0;
+ index++;
+ } else {
+ enum_length++;
+ }
+ parent_types++;
+ }
+
+ *result = index;
+ return ret;
+}
+
+/*
+ * Writes the content parent's object id to "content".
+ * Returns the metacommit type. See the METACOMMIT_TYPE_* constants.
+ */
+int get_metacommit_content(struct commit *commit, struct object_id *content)
+{
+ const char *buffer = get_commit_buffer(commit, NULL);
+ int index = 0;
+ int ret = index_of_content_commit(buffer, &index);
+ struct commit *content_parent;
+
+ if (ret == METACOMMIT_TYPE_NONE)
+ return ret;
+
+ content_parent = get_commit_by_index(commit->parents, index);
+
+ if (!content_parent)
+ return METACOMMIT_TYPE_NONE;
+
+ oidcpy(content, &(content_parent->object.oid));
+ return ret;
+}
diff --git a/metacommit-parser.h b/metacommit-parser.h
new file mode 100644
index 0000000000..1fad17dbf8
--- /dev/null
+++ b/metacommit-parser.h
@@ -0,0 +1,16 @@
+#ifndef METACOMMIT_PARSER_H
+#define METACOMMIT_PARSER_H
+
+/* Indicates a normal commit (non-metacommit) */
+#define METACOMMIT_TYPE_NONE 0
+/* Indicates a metacommit with normal content (non-abandoned) */
+#define METACOMMIT_TYPE_NORMAL 1
+/* Indicates a metacommit with abandoned content */
+#define METACOMMIT_TYPE_ABANDONED 2
+
+struct commit;
+
+extern int get_metacommit_content(
+ struct commit *commit, struct object_id *content);
+
+#endif
--
2.21.0.rc0.258.g878e2cd30e-goog
