| /* |
| * |
| * Copyright 2015, Google Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #include <grpc/support/port_platform.h> |
| |
| #ifdef GPR_POSIX_STRING |
| |
| #include <stdio.h> |
| #include <stdarg.h> |
| #include <string.h> |
| |
| #include <grpc/support/alloc.h> |
| |
| int gpr_asprintf(char **strp, const char *format, ...) { |
| va_list args; |
| int ret; |
| char buf[64]; |
| size_t strp_buflen; |
| |
| /* Use a constant-sized buffer to determine the length. */ |
| va_start(args, format); |
| ret = vsnprintf(buf, sizeof(buf), format, args); |
| va_end(args); |
| if (ret < 0) { |
| *strp = NULL; |
| return -1; |
| } |
| |
| /* Allocate a new buffer, with space for the NUL terminator. */ |
| strp_buflen = (size_t)ret + 1; |
| if ((*strp = gpr_malloc(strp_buflen)) == NULL) { |
| /* This shouldn't happen, because gpr_malloc() calls abort(). */ |
| return -1; |
| } |
| |
| /* Return early if we have all the bytes. */ |
| if (strp_buflen <= sizeof(buf)) { |
| memcpy(*strp, buf, strp_buflen); |
| return ret; |
| } |
| |
| /* Try again using the larger buffer. */ |
| va_start(args, format); |
| ret = vsnprintf(*strp, strp_buflen, format, args); |
| va_end(args); |
| if ((size_t)ret == strp_buflen - 1) { |
| return ret; |
| } |
| |
| /* This should never happen. */ |
| gpr_free(*strp); |
| *strp = NULL; |
| return -1; |
| } |
| |
| #endif /* GPR_POSIX_STRING */ |