journal: Only move to objects when necessary

Let's make sure we only move to objects when it's required. If "ret"
is NULL, the caller isn't interested in the actual object and the
function being called shouldn't move to it unless it has to
inspect/modify the object itself.

diff --git a/src/libsystemd/sd-journal/journal-file.c b/src/libsystemd/sd-journal/journal-file.c
index 55ac7c166247aa38fead581abcd9017842c78cf2..f1cbeb325a592896b4c95246acd7fe363c0e9e5a 100644 (file)
--- a/src/libsystemd/sd-journal/journal-file.c
+++ b/src/libsystemd/sd-journal/journal-file.c
@@ -758,7 +758,6 @@ int journal_file_move_to_object(JournalFile *f, ObjectType type, uint64_t offset
         uint64_t s;
 
         assert(f);
-        assert(ret);
 
         /* Objects may only be located at multiple of 64 bit */
         if (!VALID64(offset))
@@ -813,7 +812,9 @@ int journal_file_move_to_object(JournalFile *f, ObjectType type, uint64_t offset
         if (r < 0)
                 return r;
 
-        *ret = o;
+        if (ret)
+                *ret = o;
+
         return 0;
 }
 
@@ -823,7 +824,6 @@ int journal_file_read_object(JournalFile *f, ObjectType type, uint64_t offset, O
         uint64_t s;
 
         assert(f);
-        assert(ret);
 
         /* Objects may only be located at multiple of 64 bit */
         if (!VALID64(offset))
@@ -872,7 +872,9 @@ int journal_file_read_object(JournalFile *f, ObjectType type, uint64_t offset, O
         if (r < 0)
                 return r;
 
-        *ret = o;
+        if (ret)
+                *ret = o;
+
         return 0;
 }
 
@@ -1453,19 +1455,11 @@ static int journal_file_append_field(
 
         hash = journal_file_hash_data(f, field, size);
 
-        r = journal_file_find_field_object_with_hash(f, field, size, hash, &o, &p);
+        r = journal_file_find_field_object_with_hash(f, field, size, hash, ret, ret_offset);
         if (r < 0)
                 return r;
-        if (r > 0) {
-
-                if (ret)
-                        *ret = o;
-
-                if (ret_offset)
-                        *ret_offset = p;
-
+        if (r > 0)
                 return 0;
-        }
 
         osize = offsetof(Object, field.payload) + size;
         r = journal_file_append_object(f, OBJECT_FIELD, osize, &o, &p);
@@ -1479,20 +1473,20 @@ static int journal_file_append_field(
         if (r < 0)
                 return r;
 
-        /* The linking might have altered the window, so let's
-         * refresh our pointer */
-        r = journal_file_move_to_object(f, OBJECT_FIELD, p, &o);
-        if (r < 0)
-                return r;
+        /* The linking might have altered the window, so let's only pass the offset to hmac which will
+         * move to the object again if needed. */
 
 #if HAVE_GCRYPT
-        r = journal_file_hmac_put_object(f, OBJECT_FIELD, o, p);
+        r = journal_file_hmac_put_object(f, OBJECT_FIELD, NULL, p);
         if (r < 0)
                 return r;
 #endif
 
-        if (ret)
-                *ret = o;
+        if (ret) {
+                r = journal_file_move_to_object(f, OBJECT_FIELD, p, ret);
+                if (r < 0)
+                        return r;
+        }
 
         if (ret_offset)
                 *ret_offset = p;
@@ -1517,19 +1511,11 @@ static int journal_file_append_data(
 
         hash = journal_file_hash_data(f, data, size);
 
-        r = journal_file_find_data_object_with_hash(f, data, size, hash, &o, &p);
+        r = journal_file_find_data_object_with_hash(f, data, size, hash, ret, ret_offset);
         if (r < 0)
                 return r;
-        if (r > 0) {
-
-                if (ret)
-                        *ret = o;
-
-                if (ret_offset)
-                        *ret_offset = p;
-
+        if (r > 0)
                 return 0;
-        }
 
         eq = memchr(data, '=', size);
         if (!eq)
@@ -1567,17 +1553,16 @@ static int journal_file_append_data(
         if (r < 0)
                 return r;
 
-#if HAVE_GCRYPT
-        r = journal_file_hmac_put_object(f, OBJECT_DATA, o, p);
+        /* The linking might have altered the window, so let's refresh our pointer. */
+        r = journal_file_move_to_object(f, OBJECT_DATA, p, &o);
         if (r < 0)
                 return r;
-#endif
 
-        /* The linking might have altered the window, so let's
-         * refresh our pointer */
-        r = journal_file_move_to_object(f, OBJECT_DATA, p, &o);
+#if HAVE_GCRYPT
+        r = journal_file_hmac_put_object(f, OBJECT_DATA, o, p);
         if (r < 0)
                 return r;
+#endif
 
         /* Create field object ... */
         r = journal_file_append_field(f, data, (uint8_t*) eq - (uint8_t*) data, &fo, &fp);
@@ -2126,7 +2111,7 @@ static int generic_array_get(
                 direction_t direction,
                 Object **ret, uint64_t *ret_offset) {
 
-        Object *o, *e;
+        Object *o;
         uint64_t p = 0, a, t = 0, k;
         int r;
         ChainCacheItem *ci;
@@ -2178,9 +2163,16 @@ static int generic_array_get(
                 do {
                         p = le64toh(o->entry_array.items[i]);
 
-                        r = journal_file_move_to_object(f, OBJECT_ENTRY, p, &e);
-                        if (r >= 0)
-                                goto found;
+                        r = journal_file_move_to_object(f, OBJECT_ENTRY, p, ret);
+                        if (r >= 0) {
+                                /* Let's cache this item for the next invocation */
+                                chain_cache_put(f->chain_cache, ci, first, a, le64toh(o->entry_array.items[0]), t, i);
+
+                                if (ret_offset)
+                                        *ret_offset = p;
+
+                                return 1;
+                        }
                         if (!IN_SET(r, -EADDRNOTAVAIL, -EBADMSG))
                                 return r;
 
@@ -2195,18 +2187,6 @@ static int generic_array_get(
         }
 
         return 0;
-
-found:
-        /* Let's cache this item for the next invocation */
-        chain_cache_put(f->chain_cache, ci, first, a, le64toh(o->entry_array.items[0]), t, i);
-
-        if (ret)
-                *ret = e;
-
-        if (ret_offset)
-                *ret_offset = p;
-
-        return 1;
 }
 
 static int generic_array_get_plus_one(
@@ -2217,21 +2197,17 @@ static int generic_array_get_plus_one(
                 direction_t direction,
                 Object **ret, uint64_t *ret_offset) {
 
-        Object *o;
         int r;
 
         assert(f);
 
         if (i == 0) {
-                r = journal_file_move_to_object(f, OBJECT_ENTRY, extra, &o);
+                r = journal_file_move_to_object(f, OBJECT_ENTRY, extra, ret);
                 if (IN_SET(r, -EADDRNOTAVAIL, -EBADMSG))
                         return generic_array_get(f, first, 0, direction, ret, ret_offset);
                 if (r < 0)
                         return r;
 
-                if (ret)
-                        *ret = o;
-
                 if (ret_offset)
                         *ret_offset = extra;
 
@@ -2260,7 +2236,7 @@ static int generic_array_bisect(
 
         uint64_t a, p, t = 0, i = 0, last_p = 0, last_index = UINT64_MAX;
         bool subtract_one = false;
-        Object *o, *array = NULL;
+        Object *array = NULL;
         int r;
         ChainCacheItem *ci;
 
@@ -2448,12 +2424,11 @@ found:
         else
                 p = le64toh(array->entry_array.items[i]);
 
-        r = journal_file_move_to_object(f, OBJECT_ENTRY, p, &o);
-        if (r < 0)
-                return r;
-
-        if (ret)
-                *ret = o;
+        if (ret) {
+                r = journal_file_move_to_object(f, OBJECT_ENTRY, p, ret);
+                if (r < 0)
+                        return r;
+        }
 
         if (ret_offset)
                 *ret_offset = p;
@@ -2478,7 +2453,6 @@ static int generic_array_bisect_plus_one(
 
         int r;
         bool step_back = false;
-        Object *o;
 
         assert(f);
         assert(test_object);
@@ -2521,12 +2495,11 @@ static int generic_array_bisect_plus_one(
         return r;
 
 found:
-        r = journal_file_move_to_object(f, OBJECT_ENTRY, extra, &o);
-        if (r < 0)
-                return r;
-
-        if (ret)
-                *ret = o;
+        if (ret) {
+                r = journal_file_move_to_object(f, OBJECT_ENTRY, extra, ret);
+                if (r < 0)
+                        return r;
+        }
 
         if (ret_offset)
                 *ret_offset = extra;
@@ -2929,7 +2902,6 @@ int journal_file_move_to_entry_by_monotonic_for_data(
                 return r;
 
         for (;;) {
-                Object *qo;
                 uint64_t p, q;
 
                 r = generic_array_bisect_plus_one(f,
@@ -2950,14 +2922,18 @@ int journal_file_move_to_entry_by_monotonic_for_data(
                                                   p,
                                                   test_object_offset,
                                                   direction,
-                                                  &qo, &q, NULL);
+                                                  NULL, &q, NULL);
 
                 if (r <= 0)
                         return r;
 
                 if (p == q) {
-                        if (ret)
-                                *ret = qo;
+                        if (ret) {
+                                r = journal_file_move_to_object(f, OBJECT_ENTRY, q, ret);
+                                if (r < 0)
+                                        return r;
+                        }
+
                         if (ret_offset)
                                 *ret_offset = q;