4 files changed, 85 insertions, 69 deletions

diff --git a/src/journal-remote/journal-remote-parse.c b/src/journal-remote/journal-remote-parse.c
index cdc920eb4c..dfb87d49af 100644
--- a/src/journal-remote/journal-remote-parse.c
+++ b/src/journal-remote/journal-remote-parse.c
@@ -70,24 +70,38 @@ RemoteSource* source_new(int fd, bool passive_fd, char *name, Writer *writer) {
         return source;
 }
 
+static char* realloc_buffer(RemoteSource *source, size_t size) {
+        char *b, *old = source->buf;
+
+        b = GREEDY_REALLOC(source->buf, source->size, size);
+        if (!b)
+                return NULL;
+
+        iovw_rebase(&source->iovw, old, source->buf);
+
+        return b;
+}
+
 static int get_line(RemoteSource *source, char **line, size_t *size) {
-        ssize_t n, remain;
+        ssize_t n;
         char *c = NULL;
-        char *newbuf = NULL;
-        size_t newsize = 0;
 
         assert(source);
         assert(source->state == STATE_LINE);
+        assert(source->offset <= source->filled);
         assert(source->filled <= source->size);
         assert(source->buf == NULL || source->size > 0);
         assert(source->fd >= 0);
 
         while (true) {
-                if (source->buf)
-                        c = memchr(source->buf + source->scanned, '\n',
-                                   source->filled - source->scanned);
-                if (c != NULL)
-                        break;
+                if (source->buf) {
+                        size_t start = MAX(source->scanned, source->offset);
+
+                        c = memchr(source->buf + start, '\n',
+                                   source->filled - start);
+                        if (c != NULL)
+                                break;
+                }
 
                 source->scanned = source->filled;
                 if (source->scanned >= DATA_SIZE_MAX) {
@@ -100,15 +114,12 @@ static int get_line(RemoteSource *source, char **line, size_t *size) {
                         return -EWOULDBLOCK;
 
                 if (source->size - source->filled < LINE_CHUNK &&
-                    !GREEDY_REALLOC(source->buf, source->size,
-                                    MIN(source->filled + LINE_CHUNK, DATA_SIZE_MAX)))
+                    !realloc_buffer(source,
+                                    MIN(source->filled + LINE_CHUNK, ENTRY_SIZE_MAX)))
                                 return log_oom();
 
                 assert(source->size - source->filled >= LINE_CHUNK ||
-                       source->size == DATA_SIZE_MAX);
-
-                // FIXME: the buffer probably needs to be bigger than DATA_SIZE_MAX
-                // to accomodate such big fields.
+                       source->size == ENTRY_SIZE_MAX);
 
                 n = read(source->fd, source->buf + source->filled,
                          source->size - source->filled);
@@ -123,23 +134,9 @@ static int get_line(RemoteSource *source, char **line, size_t *size) {
                 source->filled += n;
         }
 
-        *line = source->buf;
-        *size = c + 1 - source->buf;
-
-        /* Check if something remains */
-        remain = source->buf + source->filled - c - 1;
-        assert(remain >= 0);
-        if (remain) {
-                newsize = MAX(remain, LINE_CHUNK);
-                newbuf = malloc(newsize);
-                if (!newbuf)
-                        return log_oom();
-                memcpy(newbuf, c + 1, remain);
-        }
-        source->buf = newbuf;
-        source->size = newsize;
-        source->filled = remain;
-        source->scanned = 0;
+        *line = source->buf + source->offset;
+        *size = c + 1 - source->buf - source->offset;
+        source->offset += *size;
 
         return 1;
 }
@@ -148,8 +145,7 @@ int push_data(RemoteSource *source, const char *data, size_t size) {
         assert(source);
         assert(source->state != STATE_EOF);
 
-        if (!GREEDY_REALLOC(source->buf, source->size,
-                            source->filled + size)) {
+        if (!realloc_buffer(source, source->filled + size)) {
                 log_error("Failed to store received data of size %zu "
                           "(in addition to existing %zu bytes with %zu filled): %s",
                           size, source->size, source->filled, strerror(ENOMEM));
@@ -163,28 +159,27 @@ int push_data(RemoteSource *source, const char *data, size_t size) {
 }
 
 static int fill_fixed_size(RemoteSource *source, void **data, size_t size) {
-        int n;
-        char *newbuf = NULL;
-        size_t newsize = 0, remain;
 
         assert(source);
         assert(source->state == STATE_DATA_START ||
                source->state == STATE_DATA ||
                source->state == STATE_DATA_FINISH);
         assert(size <= DATA_SIZE_MAX);
+        assert(source->offset <= source->filled);
         assert(source->filled <= source->size);
-        assert(source->scanned <= source->filled);
         assert(source->buf != NULL || source->size == 0);
         assert(source->buf == NULL || source->size > 0);
         assert(source->fd >= 0);
         assert(data);
 
-        while(source->filled < size) {
+        while (source->filled - source->offset < size) {
+                int n;
+
                 if (source->passive_fd)
                         /* we have to wait for some data to come to us */
                         return -EWOULDBLOCK;
 
-                if (!GREEDY_REALLOC(source->buf, source->size, size))
+                if (!realloc_buffer(source, source->offset + size))
                         return log_oom();
 
                 n = read(source->fd, source->buf + source->filled,
@@ -200,29 +195,15 @@ static int fill_fixed_size(RemoteSource *source, void **data, size_t size) {
                 source->filled += n;
         }
 
-        *data = source->buf;
-
-        /* Check if something remains */
-        assert(size <= source->filled);
-        remain = source->filled - size;
-        if (remain) {
-                newsize = MAX(remain, LINE_CHUNK);
-                newbuf = malloc(newsize);
-                if (!newbuf)
-                        return log_oom();
-                memcpy(newbuf, source->buf + size, remain);
-        }
-        source->buf = newbuf;
-        source->size = newsize;
-        source->filled = remain;
-        source->scanned = 0;
+        *data = source->buf + source->offset;
+        source->offset += size;
 
         return 1;
 }
 
 static int get_data_size(RemoteSource *source) {
         int r;
-        _cleanup_free_ void *data = NULL;
+        void *data;
 
         assert(source);
         assert(source->state == STATE_DATA_START);
@@ -260,7 +241,7 @@ static int get_data_data(RemoteSource *source, void **data) {
 
 static int get_data_newline(RemoteSource *source) {
         int r;
-        _cleanup_free_ char *data = NULL;
+        char *data;
 
         assert(source);
         assert(source->state == STATE_DATA_FINISH);
@@ -350,15 +331,12 @@ int process_data(RemoteSource *source) {
 
                 if (n == 1) {
                         log_debug("Received empty line, event is ready");
-                        free(line);
                         return 1;
                 }
 
                 r = process_dunder(source, line, n);
-                if (r != 0) {
-                        free(line);
+                if (r != 0)
                         return r < 0 ? r : 0;
-                }
 
                 /* MESSAGE=xxx\n
                    or
@@ -377,7 +355,6 @@ int process_data(RemoteSource *source) {
                 r = iovw_put(&source->iovw, line, n);
                 if (r < 0) {
                         log_error("Failed to put line in iovect");
-                        free(line);
                         return r;
                 }
 
@@ -450,6 +427,7 @@ int process_data(RemoteSource *source) {
 }
 
 int process_source(RemoteSource *source, bool compress, bool seal) {
+        size_t remain, target;
         int r;
 
         assert(source);
@@ -480,5 +458,36 @@ int process_source(RemoteSource *source, bool compress, bool seal) {
 
  freeing:
         iovw_free_contents(&source->iovw);
+
+        /* possibly reset buffer position */
+        remain = source->filled - source->offset;
+
+        if (remain == 0) /* no brainer */
+                source->offset = source->scanned = source->filled = 0;
+        else if (source->offset > source->size - source->filled &&
+                 source->offset > remain) {
+                memcpy(source->buf, source->buf + source->offset, remain);
+                source->offset = source->scanned = 0;
+                source->filled = remain;
+        }
+
+        target = source->size;
+        while (target > 16 * LINE_CHUNK && remain < target / 2)
+                target /= 2;
+        if (target < source->size) {
+                char *tmp;
+
+                tmp = realloc(source->buf, target);
+                if (tmp)
+                        log_warning("Failed to reallocate buffer to (smaller) size %zu",
+                                    target);
+                else {
+                        log_debug("Reallocated buffer from %zu to %zu bytes",
+                                  source->size, target);
+                        source->buf = tmp;
+                        source->size = target;
+                }
+        }
+
         return r;
 }
diff --git a/src/journal-remote/journal-remote-parse.h b/src/journal-remote/journal-remote-parse.h
index 07d6ddb67f..8499f4eb82 100644
--- a/src/journal-remote/journal-remote-parse.h
+++ b/src/journal-remote/journal-remote-parse.h
@@ -38,10 +38,11 @@ typedef struct RemoteSource {
         bool passive_fd;
 
         char *buf;
-        size_t size;
-        size_t scanned;
-        size_t filled;
-        size_t data_size;
+        size_t size;       /* total size of the buffer */
+        size_t offset;     /* offset to the beginning of live data in the buffer */
+        size_t scanned;    /* number of bytes since the beginning of data without a newline */
+        size_t filled;     /* total number of bytes in the buffer */
+        size_t data_size;  /* size of the binary data chunk being processed */
 
         struct iovec_wrapper iovw;
 
diff --git a/src/journal-remote/journal-remote-write.c b/src/journal-remote/journal-remote-write.c
index cdd06f9eff..bec4cb1f7b 100644
--- a/src/journal-remote/journal-remote-write.c
+++ b/src/journal-remote/journal-remote-write.c
@@ -31,8 +31,6 @@ int iovw_put(struct iovec_wrapper *iovw, void* data, size_t len) {
 }
 
 void iovw_free_contents(struct iovec_wrapper *iovw) {
-        for (size_t j = 0; j < iovw->count; j++)
-                free(iovw->iovec[j].iov_base);
         free(iovw->iovec);
         iovw->iovec = NULL;
         iovw->size_bytes = iovw->count = 0;
@@ -41,12 +39,19 @@ void iovw_free_contents(struct iovec_wrapper *iovw) {
 size_t iovw_size(struct iovec_wrapper *iovw) {
         size_t n = 0, i;
 
-        for(i = 0; i < iovw->count; i++)
+        for (i = 0; i < iovw->count; i++)
                 n += iovw->iovec[i].iov_len;
 
         return n;
 }
 
+void iovw_rebase(struct iovec_wrapper *iovw, char *old, char *new) {
+        size_t i;
+
+        for (i = 0; i < iovw->count; i++)
+                iovw->iovec[i].iov_base = (char*) iovw->iovec[i].iov_base - old + new;
+}
+
 /**********************************************************************
  **********************************************************************
  **********************************************************************/
diff --git a/src/journal-remote/journal-remote-write.h b/src/journal-remote/journal-remote-write.h
index 9c5a641d2e..aa381c661e 100644
--- a/src/journal-remote/journal-remote-write.h
+++ b/src/journal-remote/journal-remote-write.h
@@ -36,6 +36,7 @@ struct iovec_wrapper {
 int iovw_put(struct iovec_wrapper *iovw, void* data, size_t len);
 void iovw_free_contents(struct iovec_wrapper *iovw);
 size_t iovw_size(struct iovec_wrapper *iovw);
+void iovw_rebase(struct iovec_wrapper *iovw, char *old, char *new);
 
 typedef struct Writer {
         JournalFile *journal;