From d10d746d7475f9492b34ffd61367dceed5dd3372 Mon Sep 17 00:00:00 2001
From: Sergey Shevchenko <sergeygs@google.com>
Date: Thu, 25 Jan 2024 12:30:44 -0800
Subject: [PATCH] #Centipede Add `RemoteFileGetSize()` API

PiperOrigin-RevId: 601529743
---
 centipede/BUILD               |  1 +
 centipede/remote_file.cc      | 10 ++++++++++
 centipede/remote_file.h       |  4 ++++
 centipede/remote_file_test.cc | 22 +++++++++++++++++++++-
 4 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/centipede/BUILD b/centipede/BUILD
index d87f7d3d6..5c9d58d11 100644
--- a/centipede/BUILD
+++ b/centipede/BUILD
@@ -1235,6 +1235,7 @@ cc_test(
     deps = [
         ":remote_file",
         ":test_util",
+        "@com_google_absl//absl/log:check",
         "@com_google_googletest//:gtest_main",
     ],
 )
diff --git a/centipede/remote_file.cc b/centipede/remote_file.cc
index 80b324c88..48015a777 100644
--- a/centipede/remote_file.cc
+++ b/centipede/remote_file.cc
@@ -19,6 +19,7 @@
 
 #include <glob.h>
 
+#include <cstdint>
 #include <cstdio>
 #include <filesystem>  // NOLINT
 #include <memory>
@@ -138,6 +139,15 @@ ABSL_ATTRIBUTE_WEAK bool RemotePathExists(std::string_view path) {
   return std::filesystem::exists(path);
 }
 
+ABSL_ATTRIBUTE_WEAK int64_t RemoteFileGetSize(std::string_view path) {
+  FILE *f = std::fopen(path.data(), "r");
+  CHECK(f != nullptr) << VV(path);
+  std::fseek(f, 0, SEEK_END);
+  const auto sz = std::ftell(f);
+  std::fclose(f);
+  return sz;
+}
+
 namespace {
 
 int HandleGlobError(const char *epath, int eerrno) {
diff --git a/centipede/remote_file.h b/centipede/remote_file.h
index 1b4a59a75..19ca891cd 100644
--- a/centipede/remote_file.h
+++ b/centipede/remote_file.h
@@ -22,6 +22,7 @@
 #ifndef THIRD_PARTY_CENTIPEDE_REMOTE_FILE_H_
 #define THIRD_PARTY_CENTIPEDE_REMOTE_FILE_H_
 
+#include <cstdint>
 #include <filesystem>  // NOLINT
 #include <memory>
 #include <string>
@@ -75,6 +76,9 @@ void RemoteFileGetContents(const std::filesystem::path &path,
 // Returns true if `path` exists.
 bool RemotePathExists(std::string_view path);
 
+// Returns the size of the file at `path` in bytes. The file must exist.
+int64_t RemoteFileGetSize(std::string_view path);
+
 // Finds all files matching `glob` and appends them to `matches`.
 void RemoteGlobMatch(std::string_view glob, std::vector<std::string> &matches);
 
diff --git a/centipede/remote_file_test.cc b/centipede/remote_file_test.cc
index f521315b4..dbf702b18 100644
--- a/centipede/remote_file_test.cc
+++ b/centipede/remote_file_test.cc
@@ -14,6 +14,7 @@
 
 #include "./centipede/remote_file.h"
 
+#include <cstdint>
 #include <filesystem>  // NOLINT
 #include <fstream>
 #include <string>
@@ -22,6 +23,7 @@
 
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
+#include "absl/log/check.h"
 #include "./centipede/test_util.h"
 
 namespace centipede {
@@ -30,14 +32,32 @@ namespace {
 using ::testing::IsEmpty;
 using ::testing::UnorderedElementsAre;
 
-bool CreateFile(std::string_view path) {
+bool CreateFile(std::string_view path, std::string_view contents = "") {
   std::ofstream f((std::string(path)));
   if (!f) {
     return false;
   }
+  f << contents;
   return true;
 }
 
+TEST(RemoteFile, GetSize) {
+  const std::filesystem::path temp_dir{GetTestTempDir(test_info_->name())};
+  const std::string file_path = temp_dir / "file_01";
+  {
+    const std::string file_contents1 = "abcd1234";
+    CHECK(CreateFile(file_path, file_contents1));
+    const int64_t size = RemoteFileGetSize(file_path);
+    EXPECT_EQ(size, file_contents1.size());
+  }
+  {
+    const std::string file_contents2 = "efg567";
+    RemoteFileSetContents(file_path, file_contents2);
+    const int64_t size = RemoteFileGetSize(file_path);
+    EXPECT_EQ(size, file_contents2.size());
+  }
+}
+
 TEST(RemoteListFilesRecursively, ListsFilesInRecursiveDirectories) {
   auto temp_dir = std::filesystem::path(GetTestTempDir(test_info_->name()));