From 8531d6695f7363e5fa24141c53253e699d99ca0a Mon Sep 17 00:00:00 2001 From: Neels Hofmeyr Date: Thu, 11 Apr 2019 07:16:02 +0200 Subject: tweak OSMO_STRBUF_APPEND(), add OSMO_STRBUF_APPEND_NOLEN() In OSMO_STRBUF_APPEND, use local variable names that are less likely to shadow other local variables: prefix with _sb_. In OSMO_STRBUF_APPEND, add a check to add to .pos only if it is not NULL. Add OSMO_STRBUF_APPEND_NOLEN(), which works for function signatures that don't return a length. This is useful for any osmo_*_buf() string writing functions, so that these write directly to the strbuf. Change-Id: I108cadf72deb3a3bcab9a07e50572d9da1ab0359 --- include/osmocom/core/utils.h | 37 ++++++++++++++++++++++++++++++------- tests/utils/utils_test.c | 18 ++++++++++++++++++ tests/utils/utils_test.ok | 5 +++++ 3 files changed, 53 insertions(+), 7 deletions(-) diff --git a/include/osmocom/core/utils.h b/include/osmocom/core/utils.h index 474e36c4..f13c1e48 100644 --- a/include/osmocom/core/utils.h +++ b/include/osmocom/core/utils.h @@ -205,14 +205,14 @@ struct osmo_strbuf { #define OSMO_STRBUF_APPEND(STRBUF, func, args...) do { \ if (!(STRBUF).pos) \ (STRBUF).pos = (STRBUF).buf; \ - size_t remain = (STRBUF).buf ? (STRBUF).len - ((STRBUF).pos - (STRBUF).buf) : 0; \ - int l = func((STRBUF).pos, remain, ##args); \ - if (l < 0 || l > remain) \ + size_t _sb_remain = (STRBUF).buf ? (STRBUF).len - ((STRBUF).pos - (STRBUF).buf) : 0; \ + int _sb_l = func((STRBUF).pos, _sb_remain, ##args); \ + if (_sb_l < 0 || _sb_l > _sb_remain) \ (STRBUF).pos = (STRBUF).buf + (STRBUF).len; \ - else \ - (STRBUF).pos += l; \ - if (l > 0) \ - (STRBUF).chars_needed += l; \ + else if ((STRBUF).pos) \ + (STRBUF).pos += _sb_l; \ + if (_sb_l > 0) \ + (STRBUF).chars_needed += _sb_l; \ } while(0) /*! Shortcut for OSMO_STRBUF_APPEND() invocation using snprintf(). @@ -237,6 +237,29 @@ struct osmo_strbuf { #define OSMO_STRBUF_PRINTF(STRBUF, fmt, args...) \ OSMO_STRBUF_APPEND(STRBUF, snprintf, fmt, ##args) +/*! Like OSMO_STRBUF_APPEND(), but for function signatures that return the char* buffer instead of a length. + * When using this function, the final STRBUF.chars_needed may not reflect the actual number of characters needed, since + * that number cannot be obtained from this kind of function signature. + * \param[inout] STRBUF A struct osmo_strbuf instance. + * \param[in] func A function with a signature of char *func(char *dst, size_t dst_len [, args]) where + * the returned string is always written to dst. + * \param[in] args Arguments passed to func, if any. + */ +#define OSMO_STRBUF_APPEND_NOLEN(STRBUF, func, args...) do { \ + if (!(STRBUF).pos) \ + (STRBUF).pos = (STRBUF).buf; \ + size_t _sb_remain = (STRBUF).buf ? (STRBUF).len - ((STRBUF).pos - (STRBUF).buf) : 0; \ + if (_sb_remain) { \ + func((STRBUF).pos, _sb_remain, ##args); \ + } \ + size_t _sb_l = (STRBUF).pos ? strnlen((STRBUF).pos, _sb_remain) : 0; \ + if (_sb_l > _sb_remain) \ + (STRBUF).pos = (STRBUF).buf + (STRBUF).len; \ + else if ((STRBUF).pos) \ + (STRBUF).pos += _sb_l; \ + (STRBUF).chars_needed += _sb_l; \ + } while(0) + bool osmo_str_startswith(const char *str, const char *startswith_str); /*! @} */ diff --git a/tests/utils/utils_test.c b/tests/utils/utils_test.c index 211b4d1a..223f67d2 100644 --- a/tests/utils/utils_test.c +++ b/tests/utils/utils_test.c @@ -1014,6 +1014,23 @@ void strbuf_test() printf("(need %d chars, had size=63) %s\n", rc, buf); } +void strbuf_test_nolen() +{ + char buf[20]; + struct osmo_strbuf sb = { .buf = buf, .len = sizeof(buf) }; + uint8_t ubits[] = {0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 1, 0, 1, 0, 1, 0}; + printf("\n%s\n", __func__); + + OSMO_STRBUF_APPEND_NOLEN(sb, osmo_ubit_dump_buf, ubits, sizeof(ubits)); + printf("%zu: %s (need=%zu)\n", sb.len, buf, sb.chars_needed); + OSMO_STRBUF_APPEND_NOLEN(sb, osmo_ubit_dump_buf, ubits, sizeof(ubits)); + printf("more: %s (need=%zu)\n", buf, sb.chars_needed); + + sb = (struct osmo_strbuf){ .buf = buf, .len = 10 }; + OSMO_STRBUF_APPEND_NOLEN(sb, osmo_ubit_dump_buf, ubits, sizeof(ubits)); + printf("%zu: %s (need=%zu)\n", sb.len, buf, sb.chars_needed); +} + static void startswith_test_str(const char *str, const char *startswith_str, bool expect_rc) { bool rc = osmo_str_startswith(str, startswith_str); @@ -1059,6 +1076,7 @@ int main(int argc, char **argv) osmo_sockaddr_to_str_and_uint_test(); osmo_str_tolowupper_test(); strbuf_test(); + strbuf_test_nolen(); startswith_test(); return 0; } diff --git a/tests/utils/utils_test.ok b/tests/utils/utils_test.ok index 5783eb16..587c6f09 100644 --- a/tests/utils/utils_test.ok +++ b/tests/utils/utils_test.ok @@ -341,6 +341,11 @@ cascade: T minus 10 9 8 7 6 5 4 3 2 1 ... Lift off! -- T minus 10 9 8 7 6 5 4 3 2 1 ... Lift off! -- T minus 10 9 8 7 6 5 4 3 2 1 ... Lift off! (need 134 chars, had size=63) T minus 10 9 8 7 6 5 4 3 2 1 ... Lift off! -- T minus 10 9 8 7 +strbuf_test_nolen +20: 0001011100101010 (need=16) +more: 0001011100101010000 (need=19) +10: 000101110 (need=9) + startswith_test() osmo_str_startswith(NULL, NULL) == true osmo_str_startswith("", NULL) == true -- cgit v1.2.3