unix,win: add uv_os_tmpdir()

PR-URL: https://github.com/libuv/libuv/pull/672
Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>

Makefile.am

@@ -243,6 +243,7 @@ test_run_tests_SOURCES = test/blackhole-server.c \
                          test/test-timer-again.c \
                          test/test-timer-from-check.c \
                          test/test-timer.c \
+                         test/test-tmpdir.c \
                          test/test-tty.c \
                          test/test-udp-bind.c \
                          test/test-udp-create-socket-early.c \

checksparse.sh

@@ -155,6 +155,7 @@ test/test-threadpool-cancel.c
 test/test-threadpool.c
 test/test-timer-again.c
 test/test-timer.c
+test/test-tmpdir.c
 test/test-tty.c
 test/test-udp-dgram-too-big.c
 test/test-udp-ipv6.c

docs/src/misc.rst

@@ -273,6 +273,22 @@ API
 
     .. versionadded:: 1.6.0
 
+.. c:function:: int uv_os_tmpdir(char* buffer, size_t* size)
+
+    Gets the temp directory. On Windows, `uv_os_tmpdir()` uses `GetTempPathW()`.
+    On all other operating systems, `uv_os_tmpdir()` uses the first environment
+    variable found in the ordered list `TMPDIR`, `TMP`, `TEMP`, and `TEMPDIR`.
+    If none of these are found, the path `"/tmp"` is used, or, on Android,
+    `"/data/local/tmp"` is used. The temp directory is stored in `buffer`. When
+    `uv_os_tmpdir()` is called, `size` indicates the maximum size of `buffer`.
+    On success or `UV_ENOBUFS` failure, `size` is set to the string length of
+    `buffer` (which does not include the terminating null).
+
+    .. warning::
+        `uv_os_tmpdir()` is not thread safe.
+
+    .. versionadded:: 1.9.0
+
 .. uint64_t uv_get_free_memory(void)
 .. c:function:: uint64_t uv_get_total_memory(void)
 

include/uv.h

@@ -1049,6 +1049,7 @@ typedef struct {
 UV_EXTERN int uv_getrusage(uv_rusage_t* rusage);
 
 UV_EXTERN int uv_os_homedir(char* buffer, size_t* size);
+UV_EXTERN int uv_os_tmpdir(char* buffer, size_t* size);
 
 UV_EXTERN int uv_cpu_info(uv_cpu_info_t** cpu_infos, int* count);
 UV_EXTERN void uv_free_cpu_info(uv_cpu_info_t* cpu_infos, int count);

src/unix/core.c

@@ -1102,3 +1102,54 @@ int uv_os_homedir(char* buffer, size_t* size) {
 
   return 0;
 }
+
+
+int uv_os_tmpdir(char* buffer, size_t* size) {
+  const char* buf;
+  size_t len;
+
+  if (buffer == NULL || size == NULL || *size == 0)
+    return -EINVAL;
+
+#define CHECK_ENV_VAR(name)                                                   \
+  do {                                                                        \
+    buf = getenv(name);                                                       \
+    if (buf != NULL)                                                          \
+      goto return_buffer;                                                     \
+  }                                                                           \
+  while (0)
+
+  /* Check the TMPDIR, TMP, TEMP, and TEMPDIR environment variables in order */
+  CHECK_ENV_VAR("TMPDIR");
+  CHECK_ENV_VAR("TMP");
+  CHECK_ENV_VAR("TEMP");
+  CHECK_ENV_VAR("TEMPDIR");
+
+#undef CHECK_ENV_VAR
+
+  /* No temp environment variables defined */
+  #if defined(__ANDROID__)
+    buf = "/data/local/tmp";
+  #else
+    buf = "/tmp";
+  #endif
+
+return_buffer:
+  len = strlen(buf);
+
+  if (len >= *size) {
+    *size = len;
+    return -ENOBUFS;
+  }
+
+  /* The returned directory should not have a trailing slash. */
+  if (len > 1 && buf[len - 1] == '/') {
+    len--;
+  }
+
+  memcpy(buffer, buf, len + 1);
+  buffer[len] = '\0';
+  *size = len;
+
+  return 0;
+}

src/win/util.c

@@ -1230,3 +1230,56 @@ convert_buffer:
   *size = bufsize - 1;
   return 0;
 }
+
+
+int uv_os_tmpdir(char* buffer, size_t* size) {
+  wchar_t path[MAX_PATH + 1];
+  DWORD bufsize;
+  size_t len;
+
+  if (buffer == NULL || size == NULL || *size == 0)
+    return UV_EINVAL;
+
+  len = GetTempPathW(MAX_PATH + 1, path);
+
+  if (len == 0) {
+    return uv_translate_sys_error(GetLastError());
+  } else if (len > MAX_PATH + 1) {
+    /* This should not be possible */
+    return UV_EIO;
+  }
+
+  /* The returned directory should not have a trailing slash, unless it */
+  /* points at a drive root, like c:\. Remove it if needed.*/
+  if (path[len - 1] == L'\\' &&
+      !(len == 3 && path[1] == L':')) {
+    len--;
+    path[len] = L'\0';
+  }
+
+  /* Check how much space we need */
+  bufsize = WideCharToMultiByte(CP_UTF8, 0, path, -1, NULL, 0, NULL, NULL);
+
+  if (bufsize == 0) {
+    return uv_translate_sys_error(GetLastError());
+  } else if (bufsize > *size) {
+    *size = bufsize - 1;
+    return UV_ENOBUFS;
+  }
+
+  /* Convert to UTF-8 */
+  bufsize = WideCharToMultiByte(CP_UTF8,
+                                0,
+                                path,
+                                -1,
+                                buffer,
+                                *size,
+                                NULL,
+                                NULL);
+
+  if (bufsize == 0)
+    return uv_translate_sys_error(GetLastError());
+
+  *size = bufsize - 1;
+  return 0;
+}

test/test-list.h

@@ -199,6 +199,7 @@ TEST_DECLARE   (cwd_and_chdir)
 TEST_DECLARE   (get_memory)
 TEST_DECLARE   (handle_fileno)
 TEST_DECLARE   (homedir)
+TEST_DECLARE   (tmpdir)
 TEST_DECLARE   (hrtime)
 TEST_DECLARE   (getaddrinfo_fail)
 TEST_DECLARE   (getaddrinfo_fail_sync)
@@ -586,6 +587,8 @@ TASK_LIST_START
 
   TEST_ENTRY  (homedir)
 
+  TEST_ENTRY  (tmpdir)
+
   TEST_ENTRY  (hrtime)
 
   TEST_ENTRY_CUSTOM (getaddrinfo_fail, 0, 0, 10000)

test/test-tmpdir.c

@@ -0,0 +1,50 @@
+#include "uv.h"
+#include "task.h"
+#include <string.h>
+
+#define PATHMAX 1024
+#define SMALLPATH 1
+
+TEST_IMPL(tmpdir) {
+  char tmpdir[PATHMAX];
+  size_t len;
+  char last;
+  int r;
+
+  /* Test the normal case */
+  len = sizeof tmpdir;
+  tmpdir[0] = '\0';
+
+  ASSERT(strlen(tmpdir) == 0);
+  r = uv_os_tmpdir(tmpdir, &len);
+  ASSERT(r == 0);
+  ASSERT(strlen(tmpdir) == len);
+  ASSERT(len > 0);
+  ASSERT(tmpdir[len] == '\0');
+
+  if (len > 1) {
+    last = tmpdir[len - 1];
+#ifdef _WIN32
+    ASSERT(last != '\\');
+#else
+    ASSERT(last != '/');
+#endif
+  }
+
+  /* Test the case where the buffer is too small */
+  len = SMALLPATH;
+  r = uv_os_tmpdir(tmpdir, &len);
+  ASSERT(r == UV_ENOBUFS);
+  ASSERT(len > SMALLPATH);
+
+  /* Test invalid inputs */
+  r = uv_os_tmpdir(NULL, &len);
+  ASSERT(r == UV_EINVAL);
+  r = uv_os_tmpdir(tmpdir, NULL);
+  ASSERT(r == UV_EINVAL);
+  len = 0;
+  r = uv_os_tmpdir(tmpdir, &len);
+  ASSERT(r == UV_EINVAL);
+
+  return 0;
+}

uv.gyp

@@ -387,6 +387,7 @@
         'test/test-threadpool.c',
         'test/test-threadpool-cancel.c',
         'test/test-thread-equal.c',
+        'test/test-tmpdir.c',
         'test/test-mutexes.c',
         'test/test-thread.c',
         'test/test-barrier.c',