Commit 960ca1d7799e02b72ca828373c3fff04e2cf0334
2009-08-28T21:22:46
Add the git_oid_to_string() utility function Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
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diff --git a/src/git/oid.h b/src/git/oid.h
index ce02206..f3d6802 100644
--- a/src/git/oid.h
+++ b/src/git/oid.h
@@ -74,13 +74,30 @@ GIT_EXTERN(void) git_oid_pathfmt(char *str, const git_oid *oid);
/**
* Format a gid_oid into a newly allocated c-string.
- * @param oid theoid structure to format
+ * @param oid the oid structure to format
* @return the c-string; NULL if memory is exhausted. Caller must
* deallocate the string with free().
*/
GIT_EXTERN(char *) git_oid_allocfmt(const git_oid *oid);
/**
+ * Format a git_oid into a buffer as a hex format c-string.
+ * <p>
+ * If the buffer is smaller than GIT_OID_HEXSZ+1, then the resulting
+ * oid c-string will be truncated to n-1 characters. If there are
+ * any input parameter errors (out == NULL, n == 0, oid == NULL),
+ * then a pointer to an empty string is returned, so that the return
+ * value can always be printed.
+ *
+ * @param out the buffer into which the oid string is output.
+ * @param n the size of the out buffer.
+ * @param oid the oid structure to format.
+ * @return the out buffer pointer, assuming no input parameter
+ * errors, otherwise a pointer to an empty string.
+ */
+GIT_EXTERN(char *) git_oid_to_string(char *out, size_t n, const git_oid *oid);
+
+/**
* Copy an oid from one structure to another.
* @param out oid structure the result is written into.
* @param src oid structure to copy from.
diff --git a/src/oid.c b/src/oid.c
index b8fce12..97603e2 100644
--- a/src/oid.c
+++ b/src/oid.c
@@ -94,3 +94,23 @@ char *git_oid_allocfmt(const git_oid *oid)
str[GIT_OID_HEXSZ] = '\0';
return str;
}
+
+char *git_oid_to_string(char *out, size_t n, const git_oid *oid)
+{
+ char str[GIT_OID_HEXSZ];
+
+ if (!out || n == 0 || !oid)
+ return "";
+
+ n--; /* allow room for terminating NUL */
+
+ if (n > 0) {
+ git_oid_fmt(str, oid);
+ memcpy(out, str, n > GIT_OID_HEXSZ ? GIT_OID_HEXSZ : n);
+ }
+
+ out[n] = '\0';
+
+ return out;
+}
+
diff --git a/tests/t0101-oid.c b/tests/t0101-oid.c
index 4a143ab..65654b6 100644
--- a/tests/t0101-oid.c
+++ b/tests/t0101-oid.c
@@ -208,3 +208,47 @@ BEGIN_TEST(cmp_oid_pathfmt)
must_pass(strcmp(exp2, out));
END_TEST
+BEGIN_TEST(oid_to_string)
+ const char *exp = "16a0123456789abcdef4b775213c23a8bd74f5e0";
+ git_oid in;
+ char out[GIT_OID_HEXSZ + 1];
+ char *str;
+ int i;
+
+ must_pass(git_oid_mkstr(&in, exp));
+
+ /* NULL buffer pointer, returns static empty string */
+ str = git_oid_to_string(NULL, sizeof(out), &in);
+ must_be_true(str && *str == '\0' && str != out);
+
+ /* zero buffer size, returns static empty string */
+ str = git_oid_to_string(out, 0, &in);
+ must_be_true(str && *str == '\0' && str != out);
+
+ /* NULL oid pointer, returns static empty string */
+ str = git_oid_to_string(out, sizeof(out), NULL);
+ must_be_true(str && *str == '\0' && str != out);
+
+ /* n == 1, returns out as an empty string */
+ str = git_oid_to_string(out, 1, &in);
+ must_be_true(str && *str == '\0' && str == out);
+
+ for (i = 1; i < GIT_OID_HEXSZ; i++) {
+ out[i+1] = 'Z';
+ str = git_oid_to_string(out, i+1, &in);
+ /* returns out containing c-string */
+ must_be_true(str && str == out);
+ /* must be '\0' terminated */
+ must_be_true(*(str+i) == '\0');
+ /* must not touch bytes past end of string */
+ must_be_true(*(str+(i+1)) == 'Z');
+ /* i == n-1 charaters of string */
+ must_pass(strncmp(exp, out, i));
+ }
+
+ /* returns out as hex formatted c-string */
+ str = git_oid_to_string(out, sizeof(out), &in);
+ must_be_true(str && str == out && *(str+GIT_OID_HEXSZ) == '\0');
+ must_pass(strcmp(exp, out));
+END_TEST
+