From b6ade08beedcfa4c01d642ee383618b22ab09b45 Mon Sep 17 00:00:00 2001 From: Bruno Haible Date: Thu, 1 May 2008 16:49:21 +0200 Subject: [PATCH] Fix computation of newsize during reallocation. --- ChangeLog | 5 +++++ lib/getndelim2.c | 21 ++++++++++++++------- 2 files changed, 19 insertions(+), 7 deletions(-) diff --git a/ChangeLog b/ChangeLog index 03e2df740..f3b5bf936 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2008-05-01 Bruno Haible + + * lib/getndelim2.c (getndelim2): Fix newsize computation during + reallocation. Rename 'done' to 'found_delimiter'. + 2008-05-01 Jim Meyering vc-list-files: accommodate /bin/sh like the one from Solaris 10 diff --git a/lib/getndelim2.c b/lib/getndelim2.c index 04349ad7e..9dcb9feb4 100644 --- a/lib/getndelim2.c +++ b/lib/getndelim2.c @@ -76,7 +76,7 @@ getndelim2 (char **lineptr, size_t *linesize, size_t offset, size_t nmax, ssize_t bytes_stored = -1; char *ptr = *lineptr; size_t size = *linesize; - bool done = false; + bool found_delimiter; if (!ptr) { @@ -103,7 +103,8 @@ getndelim2 (char **lineptr, size_t *linesize, size_t offset, size_t nmax, flockfile (stream); - while (!done) + found_delimiter = false; + do { /* Here always ptr + size == read_pos + nbytes_avail. Also nbytes_avail > 0 || size < nmax. */ @@ -121,7 +122,7 @@ getndelim2 (char **lineptr, size_t *linesize, size_t offset, size_t nmax, if (end) { buffer_len = end - buffer + 1; - done = true; + found_delimiter = true; } } } @@ -137,7 +138,7 @@ getndelim2 (char **lineptr, size_t *linesize, size_t offset, size_t nmax, break; } if (c == delim1 || c == delim2) - done = true; + found_delimiter = true; buffer_len = 1; } @@ -145,13 +146,18 @@ getndelim2 (char **lineptr, size_t *linesize, size_t offset, size_t nmax, always (unless we get an error while reading the first byte) NUL-terminate the line buffer. */ - if (nbytes_avail < 1 + buffer_len && size < nmax) + if (nbytes_avail < buffer_len + 1 && size < nmax) { + /* Grow size proportionally, not linearly, to avoid O(n^2) + running time. */ size_t newsize = size < MIN_CHUNK ? size + MIN_CHUNK : 2 * size; char *newptr; - if (newsize < buffer_len) - newsize = buffer_len + size; + /* Increase newsize so that it becomes + >= (read_pos - ptr) + buffer_len. */ + if (newsize - (read_pos - ptr) < buffer_len + 1) + newsize = (read_pos - ptr) + buffer_len + 1; + /* Respect nmax. This handles possible integer overflow. */ if (! (size < newsize && newsize <= nmax)) newsize = nmax; @@ -193,6 +199,7 @@ getndelim2 (char **lineptr, size_t *linesize, size_t offset, size_t nmax, if (buffer && freadseek (stream, buffer_len)) goto unlock_done; } + while (!found_delimiter); /* Done - NUL terminate and return the number of bytes read. At this point we know that nbytes_avail >= 1. */ -- 2.11.0