Add tests for POSIX write.

Change-Id: I14387feb6cc34bf29a0ed9a2b5f9675f08db8f67

starboard/common/file.cc

@@ -115,4 +115,22 @@ bool SbFileDeleteRecursive(const char* path, bool preserve_root) {
   return false;
 }
 
+ssize_t WriteAll(int file, const void* data, int size) {
+  if (file < 0 || size < 0) {
+    return -1;
+  }
+  ssize_t bytes_written = 0;
+  ssize_t rv;
+  do {
+    rv = write(file, reinterpret_cast<const char*>(data) + bytes_written,
+               size - bytes_written);
+    if (rv <= 0) {
+      break;
+    }
+    bytes_written += rv;
+  } while (bytes_written < size);
+
+  return bytes_written ? bytes_written : rv;
+}
+
 }  // namespace starboard

starboard/common/file.h

@@ -42,6 +42,8 @@ void RecordFileWriteStat(int write_file_result);
 // |preserve_root|: Whether or not the root directory should be preserved.
 bool SbFileDeleteRecursive(const char* path, bool preserve_root);
 
+ssize_t WriteAll(int fd, const void* data, int size);
+
 // A class that opens an SbFile in its constructor and closes it in its
 // destructor, so the file is open for the lifetime of the object. Member
 // functions call the corresponding SbFile function.

starboard/nplb/posix_compliance/posix_file_write_test.cc

@@ -0,0 +1,169 @@
+// Copyright 2024 The Cobalt Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Writing is partially tested by some of the file helpers that create files
+// for the tests to operate on.
+
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <string>
+
+#include "starboard/common/file.h"
+#include "starboard/nplb/file_helpers.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace starboard {
+namespace nplb {
+namespace {
+
+// Sets up an empty test fixture, required for typed tests.
+template <class SbFileWriteType>
+class PosixFileWriteTest : public testing::Test {};
+
+class PosixFileWriter {
+ public:
+  static ssize_t Write(int file, char* data, size_t size) {
+    return write(file, data, size);
+  }
+};
+
+class PosixFileWriterAll {
+ public:
+  static ssize_t Write(int file, char* data, size_t size) {
+    return WriteAll(file, data, size);
+  }
+};
+
+typedef testing::Types<PosixFileWriter, PosixFileWriterAll>
+    PosixFileWriteTestTypes;
+
+TYPED_TEST_CASE(PosixFileWriteTest, PosixFileWriteTestTypes);
+
+const int kBufferLength = 16 * 1024;
+
+TYPED_TEST(PosixFileWriteTest, InvalidFileErrors) {
+  char buffer[kBufferLength] = {0};
+  int result = TypeParam::Write(-1, buffer, kBufferLength);
+  EXPECT_EQ(-1, result);
+}
+
+TYPED_TEST(PosixFileWriteTest, BasicWriting) {
+  // Choose a file size that is not an even multiple of the buffer size, but
+  // is over several times the size of the buffer.
+  const int kFileSize = kBufferLength * 16 / 3;
+  ScopedRandomFile random_file(0, ScopedRandomFile::kDontCreate);
+  const std::string& filename = random_file.filename();
+
+  int file = open(filename.c_str(), O_RDWR | O_CREAT | O_TRUNC);
+  ASSERT_TRUE(file >= 0);
+
+  // Create a bigger buffer than necessary, so we can test the memory around
+  // the portion given to SbFileRead.
+  char buffer[kBufferLength] = {0};
+
+  // Initialize to some arbitrary pattern so we can verify it later.
+  for (int i = 0; i < kBufferLength; ++i) {
+    buffer[i] = static_cast<char>(i & 0xFF);
+  }
+
+  // Read and check the whole file.
+  int total = 0;
+  while (true) {
+    if (total == kFileSize) {
+      break;
+    }
+
+    int remaining = kFileSize - total;
+    int to_write = remaining < kBufferLength ? remaining : kBufferLength;
+    int bytes_written =
+        TypeParam::Write(file, buffer + (total % kBufferLength), to_write);
+
+    // Check that we didn't write more than the buffer size.
+    EXPECT_GE(to_write, bytes_written);
+
+    // Check that we didn't get an error.
+    ASSERT_LT(0, bytes_written);
+
+    total += bytes_written;
+    EXPECT_EQ(total, lseek(file, 0, SEEK_CUR));
+  }
+
+  // Tests reading and writing from same opened file.
+  int result = fsync(file);
+  ASSERT_TRUE(result == 0);
+  int position = static_cast<int>(lseek(file, 0, SEEK_SET));
+  ASSERT_EQ(0, position);
+
+  // Read and check the whole file.
+  total = 0;
+  int previous_total = 0;
+  while (true) {
+    int bytes_read = ReadAll(file, buffer, kBufferLength);
+    if (bytes_read == 0) {
+      break;
+    }
+
+    // Check that we didn't read more than the buffer size.
+    EXPECT_GE(kBufferLength, bytes_read);
+
+    // Check that we didn't get an error.
+    ASSERT_LT(0, bytes_read);
+
+    // Do some accounting to check later.
+    previous_total = total;
+    total += bytes_read;
+
+    ScopedRandomFile::ExpectPattern(previous_total, buffer, bytes_read,
+                                    __LINE__);
+  }
+
+  // Check that we read the whole file.
+  EXPECT_EQ(kFileSize, total);
+
+  result = close(file);
+  EXPECT_TRUE(result == 0);
+}
+
+TYPED_TEST(PosixFileWriteTest, WriteZeroBytes) {
+  ScopedRandomFile random_file(0, ScopedRandomFile::kDontCreate);
+  const std::string& filename = random_file.filename();
+
+  int file = open(filename.c_str(), O_CREAT | O_EXCL | O_WRONLY);
+  ASSERT_TRUE(file >= 0);
+
+  char buffer[kBufferLength] = {0};
+
+  // Write zero bytes.
+  for (int i = 0; i < 10; ++i) {
+    int bytes_written = TypeParam::Write(file, buffer, 0);
+    EXPECT_EQ(0, bytes_written);
+  }
+
+  int result = close(file);
+  EXPECT_TRUE(result == 0);
+
+  file = open(filename.c_str(), O_RDONLY);
+  ASSERT_TRUE(file >= 0);
+  struct stat info;
+  result = fstat(file, &info);
+  EXPECT_TRUE(result == 0);
+  EXPECT_EQ(0, info.st_size);
+  result = close(file);
+  EXPECT_TRUE(result == 0);
+}
+
+}  // namespace
+}  // namespace nplb
+}  // namespace starboard

starboard/shared/modular/cobalt_layer_posix_unistd_abi_wrappers.cc

@@ -35,6 +35,12 @@ ssize_t __abi_wrap_read(int fildes, void* buf, size_t nbyte);
 ssize_t read(int fildes, void* buf, size_t nbyte) {
   return __abi_wrap_read(fildes, buf, nbyte);
 }
+
+ssize_t __abi_wrap_write(int fildes, const void* buf, size_t nbyte);
+
+ssize_t write(int fildes, const void* buf, size_t nbyte) {
+  return __abi_wrap_write(fildes, buf, nbyte);
+}
 }
 
 #endif  // SB_API_VERSION >= 16

starboard/shared/modular/starboard_layer_posix_unistd_abi_wrappers.cc

@@ -31,4 +31,8 @@ ssize_t __abi_wrap_read(int fildes, void* buf, size_t nbyte) {
   return read(fildes, buf, nbyte);
 }
 
+ssize_t __abi_wrap_write(int fildes, const void* buf, size_t nbyte) {
+  return write(fildes, buf, nbyte);
+}
+
 #endif  // SB_API_VERSION >= 16

starboard/shared/modular/starboard_layer_posix_unistd_abi_wrappers.h

@@ -58,6 +58,8 @@ SB_EXPORT musl_off_t __abi_wrap_lseek(int fildes,
 
 SB_EXPORT ssize_t __abi_wrap_read(int fildes, void* buf, size_t nbyte);
 
+SB_EXPORT ssize_t __abi_wrap_write(int fildes, const void* buf, size_t nbyte);
+
 #ifdef __cplusplus
 }  // extern "C"
 #endif

starboard/shared/win32/posix_emu/include/unistd.h

@@ -36,6 +36,9 @@ off_t sb_lseek(int fd, off_t offset, int origin);
 ssize_t sb_read(int fildes, void* buf, size_t nbyte);
 #define read sb_read
 
+ssize_t sb_write(int fd, const void* buf, size_t nbyte);
+#define write sb_write
+
 int usleep(unsigned int useconds);
 
 #ifdef __cplusplus

starboard/shared/win32/posix_emu/socket.cc

@@ -329,6 +329,14 @@ ssize_t sb_read(int fd, void* buf, size_t nbyte) {
   return _read(handle.file, buf, nbyte);
 }
 
+ssize_t sb_write(int fd, const void* buf, size_t nbyte) {
+  FileOrSocket handle = handle_db_get(fd, false);
+  if (!handle.is_file) {
+    return -1;
+  }
+  return write(handle.file, buf, nbyte);
+}
+
 int sb_bind(int socket, const struct sockaddr* address, socklen_t address_len) {
   SOCKET socket_handle = handle_db_get(socket, false).socket;
   if (socket_handle == INVALID_SOCKET) {

third_party/musl/src/starboard/network/socket.c

@@ -423,6 +423,25 @@ ssize_t read(int fildes, void* buf, size_t nbyte) {
   return (ssize_t)SbFileRead(fileOrSock->file, buf, (int)nbyte);
 }
 
+ ssize_t write(int fildes, const void* buf, size_t nbyte) {
+  if (fildes < 0) {
+    errno = EBADF;
+    return -1;
+  }
+
+  FileOrSocket* fileOrSock = NULL;
+  if (get(fildes, false, &fileOrSock) != 0) {
+    errno = EBADF;
+    return -1;
+  }
+
+  if (fileOrSock == NULL || !fileOrSock->is_file) {
+    errno = EBADF;
+    return -1;
+  }
+   return (ssize_t)SbFileWrite(fileOrSock->file, buf, (int)nbyte);
+ }
+
 int socket(int domain, int type, int protocol){
   int address_type, socket_protocol;
   switch (domain){