fastboot driver: RunAndReadBuffer don't allocate too much mem

Instead of allocating the buffer for the whole
upload (which can be arbitrary number of bytes as
the device determines), read 1 MiB at a time.

Test: pass
Bug: 173654501
Change-Id: Ib601b0341b10b7dccbb429cd21aad86a2d3bfda8

fastboot/Android.bp

@@ -76,6 +76,7 @@ cc_library_host_static {
 
     header_libs: [
         "bootimg_headers",
+        "libstorage_literals_headers",
     ],
 
     export_header_lib_headers: [
@@ -275,6 +276,9 @@ cc_library_host_static {
     // Only version the final binaries
     use_version_lib: false,
     static_libs: ["libbuildversion"],
+    header_libs: [
+        "libstorage_literals_headers",
+    ],
 
     generated_headers: ["platform_tools_version"],
 

fastboot/fastboot_driver.cpp

@@ -45,11 +45,13 @@
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <android-base/unique_fd.h>
+#include <storage_literals/storage_literals.h>
 
 #include "constants.h"
 #include "transport.h"
 
 using android::base::StringPrintf;
+using namespace android::storage_literals;
 
 namespace fastboot {
 
@@ -316,12 +318,20 @@ RetCode FastBootDriver::RunAndReadBuffer(
         return BAD_DEV_RESP;
     }
 
-    std::vector<char> data(dsize);
-    if ((ret = ReadBuffer(data.data(), data.size())) != SUCCESS) {
-        return ret;
-    }
-    if ((ret = write_fn(data.data(), data.size())) != SUCCESS) {
-        return ret;
+    const uint64_t total_size = dsize;
+    const uint64_t buf_size = std::min<uint64_t>(total_size, 1_MiB);
+    std::vector<char> data(buf_size);
+    uint64_t current_offset = 0;
+    while (current_offset < total_size) {
+        uint64_t remaining = total_size - current_offset;
+        uint64_t chunk_size = std::min(buf_size, remaining);
+        if ((ret = ReadBuffer(data.data(), chunk_size)) != SUCCESS) {
+            return ret;
+        }
+        if ((ret = write_fn(data.data(), chunk_size)) != SUCCESS) {
+            return ret;
+        }
+        current_offset += chunk_size;
     }
     return HandleResponse(response, info);
 }

fs_mgr/libstorage_literals/Android.bp

@@ -8,4 +8,9 @@ cc_library_headers {
     host_supported: true,
     recovery_available: true,
     export_include_dirs: ["."],
+    target: {
+        windows: {
+            enabled: true,
+        },
+    },
 }