io: fix splice for copying unknown lengths

src/apk_io.h

@@ -77,9 +77,11 @@ struct apk_ostream *apk_ostream_counter(off_t *);
 struct apk_istream *apk_istream_from_fd_pid(int fd, pid_t pid, int (*translate_status)(int));
 struct apk_istream *apk_istream_from_file(int atfd, const char *file);
 struct apk_istream *apk_istream_from_file_gz(int atfd, const char *file);
-struct apk_istream *apk_istream_from_url(const char *url);
+struct apk_istream *apk_istream_from_fd_url(int atfd, const char *url);
 struct apk_istream *apk_istream_from_url_gz(const char *url);
 size_t apk_istream_skip(struct apk_istream *istream, size_t size);
+
+#define APK_SPLICE_ALL 0xffffffff
 size_t apk_istream_splice(void *stream, int fd, size_t size,
 			  apk_progress_cb cb, void *cb_ctx);
 
@@ -87,11 +89,15 @@ static inline struct apk_istream *apk_istream_from_fd(int fd)
 {
 	return apk_istream_from_fd_pid(fd, 0, NULL);
 }
+static inline struct apk_istream *apk_istream_from_url(const char *url)
+{
+	return apk_istream_from_fd_url(-1, url);
+}
 
 struct apk_bstream *apk_bstream_from_istream(struct apk_istream *istream);
 struct apk_bstream *apk_bstream_from_fd_pid(int fd, pid_t pid, int (*translate_status)(int));
 struct apk_bstream *apk_bstream_from_file(int atfd, const char *file);
-struct apk_bstream *apk_bstream_from_url(const char *url);
+struct apk_bstream *apk_bstream_from_fd_url(int atfd, const char *url);
 struct apk_bstream *apk_bstream_tee(struct apk_bstream *from, int atfd, const char *to);
 
 static inline struct apk_bstream *apk_bstream_from_fd(int fd)
@@ -99,6 +105,11 @@ static inline struct apk_bstream *apk_bstream_from_fd(int fd)
 	return apk_bstream_from_fd_pid(fd, 0, NULL);
 }
 
+static inline struct apk_bstream *apk_bstream_from_url(const char *url)
+{
+	return apk_bstream_from_fd_url(-1, url);
+}
+
 struct apk_ostream *apk_ostream_to_fd(int fd);
 struct apk_ostream *apk_ostream_to_file(int atfd, const char *file, const char *tmpfile, mode_t mode);
 struct apk_ostream *apk_ostream_to_file_gz(int atfd, const char *file, const char *tmpfile, mode_t mode);

src/io.c

@@ -138,7 +138,7 @@ size_t apk_istream_splice(void *stream, int fd, size_t size,
 
 	bufsz = size;
 	if (size > 128 * 1024) {
-		if (ftruncate(fd, size) == 0)
+		if (size != APK_SPLICE_ALL && ftruncate(fd, size) == 0)
 			mmapbase = mmap(NULL, size, PROT_READ | PROT_WRITE,
 					MAP_SHARED, fd, 0);
 		if (bufsz > 2*1024*1024)
@@ -165,6 +165,8 @@ size_t apk_istream_splice(void *stream, int fd, size_t size,
 		r = is->read(is, buf, togo);
 		if (r < 0)
 			goto err;
+		if (r == 0)
+			break;
 
 		if (mmapbase == MAP_FAILED) {
 			if (write(fd, buf, r) != r) {

src/url.c

@@ -86,13 +86,13 @@ static int fork_wget(const char *url, pid_t *ppid)
 	return fds[0];
 }
 
-struct apk_istream *apk_istream_from_url(const char *url)
+struct apk_istream *apk_istream_from_fd_url(int atfd, const char *url)
 {
 	pid_t pid;
 	int fd;
 
-	if (apk_url_local_file(url) != NULL)
-		return apk_istream_from_file(AT_FDCWD, apk_url_local_file(url));
+	if (atfd >= 0 && apk_url_local_file(url) != NULL)
+		return apk_istream_from_file(atfd, apk_url_local_file(url));
 
 	fd = fork_wget(url, &pid);
 	return apk_istream_from_fd_pid(fd, pid, translate_wget);
@@ -103,13 +103,13 @@ struct apk_istream *apk_istream_from_url_gz(const char *file)
 	return apk_bstream_gunzip(apk_bstream_from_url(file));
 }
 
-struct apk_bstream *apk_bstream_from_url(const char *url)
+struct apk_bstream *apk_bstream_from_fd_url(int atfd, const char *url)
 {
 	pid_t pid;
 	int fd;
 
-	if (apk_url_local_file(url))
-		return apk_bstream_from_file(AT_FDCWD, url);
+	if (atfd >= 0 && apk_url_local_file(url))
+		return apk_bstream_from_file(atfd, url);
 
 	fd = fork_wget(url, &pid);
 	return apk_bstream_from_fd_pid(fd, pid, translate_wget);