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author | Ludovic Courtès <ludo@gnu.org> | 2022-02-05 23:27:48 +0100 |
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committer | Ludovic Courtès <ludo@gnu.org> | 2022-02-07 12:23:35 +0100 |
commit | 032acdeac9dfe6b407a1fcbd9f00c3e1a0dd27aa (patch) | |
tree | c1d6a755728448d1413d576c742a6a6ee165c446 /libguile/strings.c | |
parent | 2f9bc7fe61d39658a24a15526b7b88bbd184961b (diff) | |
download | guile-032acdeac9dfe6b407a1fcbd9f00c3e1a0dd27aa.tar.gz |
'string->symbol' avoids copying the underlying string.
* libguile/strings.c (scm_i_make_symbol): Reuse NAME's stringbuf unless
it's mutable or NAME starts at a non-zero offset or has a different
length.
Diffstat (limited to 'libguile/strings.c')
-rw-r--r-- | libguile/strings.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/libguile/strings.c b/libguile/strings.c index a5b4b0386..5eebb3300 100644 --- a/libguile/strings.c +++ b/libguile/strings.c @@ -763,10 +763,16 @@ SCM scm_i_make_symbol (SCM name, scm_t_bits flags, unsigned long hash) { SCM buf, symbol; - size_t length = STRING_LENGTH (name); + size_t start, length = STRING_LENGTH (name); - name = scm_i_substring_copy (name, 0, length); - buf = STRING_STRINGBUF (name); + get_str_buf_start (&name, &buf, &start); + if (SCM_UNLIKELY (STRINGBUF_MUTABLE (buf) + || start != 0 + || STRINGBUF_LENGTH (buf) != length)) + { + name = scm_i_substring_copy (name, 0, length); + buf = STRING_STRINGBUF (name); + } symbol = scm_words (scm_tc7_symbol | flags, 3); SCM_SET_CELL_WORD_1 (symbol, SCM_UNPACK (buf)); |