| Message ID | 20161018113212.GI7148@barisone |
|---|---|
| State | Superseded |
| Headers | show |
On Tue, Oct 18, 2016 at 01:32:12PM +0200, Stefano Sabatini wrote: > On date Thursday 2016-10-13 21:59:19 +0200, Michael Niedermayer encoded: > > On Thu, Oct 13, 2016 at 07:40:59PM +0200, Stefano Sabatini wrote: > > > This allows to probe if the read line was partially discarded. > > > --- > > > libavformat/aviobuf.c | 10 +++++++++- > > > libavformat/internal.h | 14 ++++++++++++++ > > > 2 files changed, 23 insertions(+), 1 deletion(-) > > > > > > diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c > > > index 134d627..28183b4 100644 > > > --- a/libavformat/aviobuf.c > > > +++ b/libavformat/aviobuf.c > > > @@ -764,18 +764,26 @@ unsigned int avio_rb32(AVIOContext *s) > > > > > > int ff_get_line(AVIOContext *s, char *buf, int maxlen) > > > { > > > - int i = 0; > > > + return ff_get_line2(s, buf, maxlen, NULL); > > > +} > > > + > > > +int ff_get_line2(AVIOContext *s, char *buf, int maxlen, int *readlen) > > > +{ > > > + int i = 0, j = 0; > > > char c; > > > > > > do { > > > c = avio_r8(s); > > > if (c && i < maxlen-1) > > > buf[i++] = c; > > > + j++; > > > } while (c != '\n' && c != '\r' && c); > > > > > "\n" and "\0" would i belive both have a j=1 but they would have > > differig i > > is that intended ? (seems to me that this would make truncation > > detection more annoying) > > or am i missing something that avoids this difference? > > Improved version in attachment. > -- > FFmpeg = Fascinating Foolish Mystic Puritan Egregious Gymnast > aviobuf.c | 18 +++++++++++++++--- > internal.h | 14 ++++++++++++++ > 2 files changed, 29 insertions(+), 3 deletions(-) > 19b979c45f087997ac69fba2caf5504c933acfc8 0001-lavf-aviobuf-add-ff_get_line2-variant.patch > From 58c1cad434447d48246e153e3a1a391d72d23c7b Mon Sep 17 00:00:00 2001 > From: Stefano Sabatini <stefasab@gmail.com> > Date: Thu, 13 Oct 2016 16:36:30 +0200 > Subject: [PATCH] lavf/aviobuf: add ff_get_line2() variant > > This allows to probe if the read line was partially discarded. > --- > libavformat/aviobuf.c | 18 +++++++++++++++--- > libavformat/internal.h | 14 ++++++++++++++ > 2 files changed, 29 insertions(+), 3 deletions(-) > > diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c > index 134d627..29bcf1e 100644 > --- a/libavformat/aviobuf.c > +++ b/libavformat/aviobuf.c > @@ -764,18 +764,30 @@ unsigned int avio_rb32(AVIOContext *s) > > int ff_get_line(AVIOContext *s, char *buf, int maxlen) > { > - int i = 0; > + return ff_get_line2(s, buf, maxlen, NULL); > +} > + > +int ff_get_line2(AVIOContext *s, char *buf, int maxlen, int *readlen) > +{ > + int i = 0, j = 0; > char c; > > + while (1) { > c = avio_r8(s); > if (c && i < maxlen-1) > buf[i++] = c; > + if (c != '\n' && c != '\r' && c) { > + j++; > + } else { > + break; > + } > + } a string like "\n" would have a strlen of 1 but readlen of 0 while a string like "X" would have a strlen and readlen of 1 is this difference intended ? or maybe i misread the code [...]
From 58c1cad434447d48246e153e3a1a391d72d23c7b Mon Sep 17 00:00:00 2001 From: Stefano Sabatini <stefasab@gmail.com> Date: Thu, 13 Oct 2016 16:36:30 +0200 Subject: [PATCH] lavf/aviobuf: add ff_get_line2() variant This allows to probe if the read line was partially discarded. --- libavformat/aviobuf.c | 18 +++++++++++++++--- libavformat/internal.h | 14 ++++++++++++++ 2 files changed, 29 insertions(+), 3 deletions(-) diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c index 134d627..29bcf1e 100644 --- a/libavformat/aviobuf.c +++ b/libavformat/aviobuf.c @@ -764,18 +764,30 @@ unsigned int avio_rb32(AVIOContext *s) int ff_get_line(AVIOContext *s, char *buf, int maxlen) { - int i = 0; + return ff_get_line2(s, buf, maxlen, NULL); +} + +int ff_get_line2(AVIOContext *s, char *buf, int maxlen, int *readlen) +{ + int i = 0, j = 0; char c; - do { + while (1) { c = avio_r8(s); if (c && i < maxlen-1) buf[i++] = c; - } while (c != '\n' && c != '\r' && c); + if (c != '\n' && c != '\r' && c) { + j++; + } else { + break; + } + } if (c == '\r' && avio_r8(s) != '\n' && !avio_feof(s)) avio_skip(s, -1); buf[i] = 0; + if (readlen) + *readlen = j; return i; } diff --git a/libavformat/internal.h b/libavformat/internal.h index 49244fa..fc49571 100644 --- a/libavformat/internal.h +++ b/libavformat/internal.h @@ -274,6 +274,20 @@ void ff_put_v(AVIOContext *bc, uint64_t val); */ int ff_get_line(AVIOContext *s, char *buf, int maxlen); +/** + * Read a whole line of text from AVIOContext. Stop reading after reaching + * either a \\n, a \\0 or EOF. The returned string is always \\0-terminated, + * and may be truncated if the buffer is too small. + * + * @param s the read-only AVIOContext + * @param buf buffer to store the read line + * @param maxlen size of the buffer + * @param readlen length of the read line, not including the final \\0 + * @return the length of the string written in the buffer, not including the + * final \\0 + */ +int ff_get_line2(AVIOContext *s, char *buf, int maxlen, int *readlen); + #define SPACE_CHARS " \t\r\n" /** -- 1.9.1