[#276] Merge repo with frostfs-api-go

Signed-off-by: Pavel Pogodaev <p.pogodaev@yadro.com>

api/container/attributes.go

@@ -0,0 +1,90 @@
+package container
+
+// SysAttributePrefix is a prefix of key to system attribute.
+const SysAttributePrefix = "__SYSTEM__"
+
+const (
+	// SysAttributeName is a string of human-friendly container name registered as the domain in NNS contract.
+	SysAttributeName = SysAttributePrefix + "NAME"
+
+	// SysAttributeZone is a string of zone for container name.
+	SysAttributeZone = SysAttributePrefix + "ZONE"
+
+	// SysAttributeHomomorphicHashing is a container's homomorphic hashing state.
+	SysAttributeHomomorphicHashing = SysAttributePrefix + "DISABLE_HOMOMORPHIC_HASHING"
+)
+
+// SysAttributePrefixNeoFS is a prefix of key to system attribute.
+// Deprecated: use SysAttributePrefix.
+const SysAttributePrefixNeoFS = "__NEOFS__"
+
+const (
+	// SysAttributeNameNeoFS is a string of human-friendly container name registered as the domain in NNS contract.
+	// Deprecated: use SysAttributeName.
+	SysAttributeNameNeoFS = SysAttributePrefixNeoFS + "NAME"
+
+	// SysAttributeZoneNeoFS is a string of zone for container name.
+	// Deprecated: use SysAttributeZone.
+	SysAttributeZoneNeoFS = SysAttributePrefixNeoFS + "ZONE"
+
+	// SysAttributeHomomorphicHashingNeoFS is a container's homomorphic hashing state.
+	// Deprecated: use SysAttributeHomomorphicHashing.
+	SysAttributeHomomorphicHashingNeoFS = SysAttributePrefixNeoFS + "DISABLE_HOMOMORPHIC_HASHING"
+)
+
+// SysAttributeZoneDefault is a default value for SysAttributeZone attribute.
+const SysAttributeZoneDefault = "container"
+
+const disabledHomomorphicHashingValue = "true"
+
+// HomomorphicHashingState returns container's homomorphic
+// hashing state:
+//   - true if hashing is enabled;
+//   - false if hashing is disabled.
+//
+// All container's attributes must be unique, otherwise behavior
+// is undefined.
+//
+// See also SetHomomorphicHashingState.
+func (c Container) HomomorphicHashingState() bool {
+	for i := range c.attr {
+		if c.attr[i].GetKey() == SysAttributeHomomorphicHashing || c.attr[i].GetKey() == SysAttributeHomomorphicHashingNeoFS {
+			return c.attr[i].GetValue() != disabledHomomorphicHashingValue
+		}
+	}
+
+	return true
+}
+
+// SetHomomorphicHashingState sets homomorphic hashing state for
+// container.
+//
+// All container's attributes must be unique, otherwise behavior
+// is undefined.
+//
+// See also HomomorphicHashingState.
+func (c *Container) SetHomomorphicHashingState(enable bool) {
+	for i := range c.attr {
+		if c.attr[i].GetKey() == SysAttributeHomomorphicHashing || c.attr[i].GetKey() == SysAttributeHomomorphicHashingNeoFS {
+			if enable {
+				// approach without allocation/waste
+				// coping works since the attributes
+				// order is not important
+				c.attr[i] = c.attr[len(c.attr)-1]
+				c.attr = c.attr[:len(c.attr)-1]
+			} else {
+				c.attr[i].SetValue(disabledHomomorphicHashingValue)
+			}
+
+			return
+		}
+	}
+
+	if !enable {
+		attr := Attribute{}
+		attr.SetKey(SysAttributeHomomorphicHashing)
+		attr.SetValue(disabledHomomorphicHashingValue)
+
+		c.attr = append(c.attr, attr)
+	}
+}