fastboot: show progress when sending sparse images.

Bug: http://b/25443220
Change-Id: Ica0c88aea2a0661f39ff1415ebba464c037651da

fastboot/engine.cpp

@@ -157,17 +157,17 @@ void fb_queue_flash(const char *ptn, void *data, unsigned sz)
     a->msg = mkmsg("writing '%s'", ptn);
 }
 
-void fb_queue_flash_sparse(const char *ptn, struct sparse_file *s, unsigned sz)
-{
+void fb_queue_flash_sparse(const char* ptn, struct sparse_file* s, unsigned sz, size_t current,
+                           size_t total) {
     Action *a;
 
     a = queue_action(OP_DOWNLOAD_SPARSE, "");
     a->data = s;
     a->size = 0;
-    a->msg = mkmsg("sending sparse '%s' (%d KB)", ptn, sz / 1024);
+    a->msg = mkmsg("sending sparse '%s' %zu/%zu (%d KB)", ptn, current, total, sz / 1024);
 
     a = queue_action(OP_COMMAND, "flash:%s", ptn);
-    a->msg = mkmsg("writing '%s'", ptn);
+    a->msg = mkmsg("writing '%s' %zu/%zu", ptn, current, total);
 }
 
 static int match(const char* str, const char** value, unsigned count) {

fastboot/fastboot.cpp

@@ -43,6 +43,8 @@
 #include <sys/types.h>
 #include <unistd.h>
 #include <functional>
+#include <utility>
+#include <vector>
 
 #include <android-base/parseint.h>
 #include <android-base/strings.h>
@@ -705,13 +707,22 @@ static void flash_buf(const char *pname, struct fastboot_buffer *buf)
     sparse_file** s;
 
     switch (buf->type) {
-        case FB_BUFFER_SPARSE:
+        case FB_BUFFER_SPARSE: {
+            std::vector<std::pair<sparse_file*, int64_t>> sparse_files;
             s = reinterpret_cast<sparse_file**>(buf->data);
             while (*s) {
                 int64_t sz = sparse_file_len(*s, true, false);
-                fb_queue_flash_sparse(pname, *s++, sz);
+                sparse_files.emplace_back(*s, sz);
+                ++s;
+            }
+
+            for (size_t i = 0; i < sparse_files.size(); ++i) {
+                const auto& pair = sparse_files[i];
+                fb_queue_flash_sparse(pname, pair.first, pair.second, i + 1, sparse_files.size());
             }
             break;
+        }
+
         case FB_BUFFER:
             fb_queue_flash(pname, buf->data, buf->sz);
             break;

fastboot/fastboot.h

@@ -51,7 +51,8 @@ char *fb_get_error(void);
 /* engine.c - high level command queue engine */
 bool fb_getvar(Transport* transport, const std::string& key, std::string* value);
 void fb_queue_flash(const char *ptn, void *data, uint32_t sz);
-void fb_queue_flash_sparse(const char *ptn, struct sparse_file *s, uint32_t sz);
+void fb_queue_flash_sparse(const char* ptn, struct sparse_file* s, uint32_t sz, size_t current,
+                           size_t total);
 void fb_queue_erase(const char *ptn);
 void fb_queue_format(const char *ptn, int skip_if_not_supported, int32_t max_chunk_sz);
 void fb_queue_require(const char *prod, const char *var, bool invert,