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authorTobias Klauser <tklauser@distanz.ch>2008-04-14 22:00:16 +0200
committerTobias Klauser <tklauser@xenon.tklauser.home>2008-04-14 22:00:16 +0200
commit63993df448640d59812131bb4db664b2ce3b285a (patch)
tree9f34fd8f157decb76d74d4e9a4242ea458a8e625
parent14acc093e702688e9680415e51d53794e075475b (diff)
inotail.c: Comment some oarts of tail_pipe_lines/tail_pipe_bytes
-rw-r--r--inotail.c25
1 files changed, 20 insertions, 5 deletions
diff --git a/inotail.c b/inotail.c
index 578d9c1..4195e13 100644
--- a/inotail.c
+++ b/inotail.c
@@ -233,6 +233,8 @@ static off_t bytes_to_offset(struct file_struct *f, unsigned long n_bytes)
} else if ((off_t) n_bytes < f->size)
offset = f->size - (off_t) n_bytes;
+ /* Otherwise offset stays 0 (begin of file) */
+
return offset;
}
@@ -295,7 +297,7 @@ static int tail_pipe_lines(struct file_struct *f, unsigned long n_lines)
return tail_pipe_from_begin(f, n_lines, M_LINES);
if (n_lines == 0)
- return 0;
+ return 0; /* No lines to tail */
first = last = emalloc(sizeof(struct line_buf));
first->n_bytes = first->n_lines = 0;
@@ -307,7 +309,7 @@ static int tail_pipe_lines(struct file_struct *f, unsigned long n_lines)
if (rc < 0 && (errno == EINTR || errno == EAGAIN))
continue;
else
- break;
+ break; /* No more data to read */
}
tmp->n_bytes = rc;
tmp->n_lines = 0;
@@ -329,7 +331,12 @@ static int tail_pipe_lines(struct file_struct *f, unsigned long n_lines)
last->n_bytes += tmp->n_bytes;
last->n_lines += tmp->n_lines;
} else {
- last = last->next = tmp;
+ /* Add buffer to the list */
+ last->next = tmp;
+ last = last->next;
+ /* We read more than n_lines lines, reuse the first
+ * buffer.
+ */
if (total_lines - first->n_lines > n_lines) {
tmp = first;
total_lines -= first->n_lines;
@@ -361,6 +368,7 @@ static int tail_pipe_lines(struct file_struct *f, unsigned long n_lines)
p = tmp->buf;
+ /* Read too many lines, advance */
if (total_lines > n_lines) {
unsigned long j;
for (j = total_lines - n_lines; j; --j) {
@@ -392,6 +400,7 @@ out:
return rc;
}
+/* TODO: Merge some parts (especially buffer handling) with tail_pipe_lines() */
static int tail_pipe_bytes(struct file_struct *f, unsigned long n_bytes)
{
struct char_buf *first, *last, *tmp;
@@ -416,7 +425,7 @@ static int tail_pipe_bytes(struct file_struct *f, unsigned long n_bytes)
if (rc < 0 && (errno == EINTR || errno == EAGAIN))
continue;
else
- break;
+ break; /* No more data to read */
}
total_bytes += rc;
tmp->n_bytes = rc;
@@ -429,7 +438,12 @@ static int tail_pipe_bytes(struct file_struct *f, unsigned long n_bytes)
memcpy(&last->buf[last->n_bytes], tmp->buf, tmp->n_bytes);
last->n_bytes += tmp->n_bytes;
} else {
- last = last->next = tmp;
+ /* Add buffer to the list */
+ last->next = tmp;
+ last = last->next;
+ /* We read more than n_bytess bytes, reuse the first
+ * buffer.
+ */
if (total_bytes - first->n_bytes > n_bytes) {
tmp = first;
total_bytes -= first->n_bytes;
@@ -450,6 +464,7 @@ static int tail_pipe_bytes(struct file_struct *f, unsigned long n_bytes)
for (tmp = first; total_bytes - tmp->n_bytes > n_bytes; tmp = tmp->next)
total_bytes -= tmp->n_bytes;
+ /* Read too many bytes, advance */
if (total_bytes > n_bytes)
i = total_bytes - n_bytes;