1 files changed, 193 insertions, 0 deletions
diff --git a/vendor/github.com/hashicorp/terraform/config/merge.go b/vendor/github.com/hashicorp/terraform/config/merge.go
new file mode 100644
index 00000000..db214be4
--- /dev/null
+++ b/vendor/github.com/hashicorp/terraform/config/merge.go
@@ -0,0 +1,193 @@
+package config
+
+// Merge merges two configurations into a single configuration.
+//
+// Merge allows for the two configurations to have duplicate resources,
+// because the resources will be merged. This differs from a single
+// Config which must only have unique resources.
+func Merge(c1, c2 *Config) (*Config, error) {
+	c := new(Config)
+
+	// Merge unknown keys
+	unknowns := make(map[string]struct{})
+	for _, k := range c1.unknownKeys {
+		_, present := unknowns[k]
+		if !present {
+			unknowns[k] = struct{}{}
+			c.unknownKeys = append(c.unknownKeys, k)
+		}
+	}
+	for _, k := range c2.unknownKeys {
+		_, present := unknowns[k]
+		if !present {
+			unknowns[k] = struct{}{}
+			c.unknownKeys = append(c.unknownKeys, k)
+		}
+	}
+
+	// Merge Atlas configuration. This is a dumb one overrides the other
+	// sort of merge.
+	c.Atlas = c1.Atlas
+	if c2.Atlas != nil {
+		c.Atlas = c2.Atlas
+	}
+
+	// Merge the Terraform configuration
+	if c1.Terraform != nil {
+		c.Terraform = c1.Terraform
+		if c2.Terraform != nil {
+			c.Terraform.Merge(c2.Terraform)
+		}
+	} else {
+		c.Terraform = c2.Terraform
+	}
+
+	// NOTE: Everything below is pretty gross. Due to the lack of generics
+	// in Go, there is some hoop-jumping involved to make this merging a
+	// little more test-friendly and less repetitive. Ironically, making it
+	// less repetitive involves being a little repetitive, but I prefer to
+	// be repetitive with things that are less error prone than things that
+	// are more error prone (more logic). Type conversions to an interface
+	// are pretty low-error.
+
+	var m1, m2, mresult []merger
+
+	// Modules
+	m1 = make([]merger, 0, len(c1.Modules))
+	m2 = make([]merger, 0, len(c2.Modules))
+	for _, v := range c1.Modules {
+		m1 = append(m1, v)
+	}
+	for _, v := range c2.Modules {
+		m2 = append(m2, v)
+	}
+	mresult = mergeSlice(m1, m2)
+	if len(mresult) > 0 {
+		c.Modules = make([]*Module, len(mresult))
+		for i, v := range mresult {
+			c.Modules[i] = v.(*Module)
+		}
+	}
+
+	// Outputs
+	m1 = make([]merger, 0, len(c1.Outputs))
+	m2 = make([]merger, 0, len(c2.Outputs))
+	for _, v := range c1.Outputs {
+		m1 = append(m1, v)
+	}
+	for _, v := range c2.Outputs {
+		m2 = append(m2, v)
+	}
+	mresult = mergeSlice(m1, m2)
+	if len(mresult) > 0 {
+		c.Outputs = make([]*Output, len(mresult))
+		for i, v := range mresult {
+			c.Outputs[i] = v.(*Output)
+		}
+	}
+
+	// Provider Configs
+	m1 = make([]merger, 0, len(c1.ProviderConfigs))
+	m2 = make([]merger, 0, len(c2.ProviderConfigs))
+	for _, v := range c1.ProviderConfigs {
+		m1 = append(m1, v)
+	}
+	for _, v := range c2.ProviderConfigs {
+		m2 = append(m2, v)
+	}
+	mresult = mergeSlice(m1, m2)
+	if len(mresult) > 0 {
+		c.ProviderConfigs = make([]*ProviderConfig, len(mresult))
+		for i, v := range mresult {
+			c.ProviderConfigs[i] = v.(*ProviderConfig)
+		}
+	}
+
+	// Resources
+	m1 = make([]merger, 0, len(c1.Resources))
+	m2 = make([]merger, 0, len(c2.Resources))
+	for _, v := range c1.Resources {
+		m1 = append(m1, v)
+	}
+	for _, v := range c2.Resources {
+		m2 = append(m2, v)
+	}
+	mresult = mergeSlice(m1, m2)
+	if len(mresult) > 0 {
+		c.Resources = make([]*Resource, len(mresult))
+		for i, v := range mresult {
+			c.Resources[i] = v.(*Resource)
+		}
+	}
+
+	// Variables
+	m1 = make([]merger, 0, len(c1.Variables))
+	m2 = make([]merger, 0, len(c2.Variables))
+	for _, v := range c1.Variables {
+		m1 = append(m1, v)
+	}
+	for _, v := range c2.Variables {
+		m2 = append(m2, v)
+	}
+	mresult = mergeSlice(m1, m2)
+	if len(mresult) > 0 {
+		c.Variables = make([]*Variable, len(mresult))
+		for i, v := range mresult {
+			c.Variables[i] = v.(*Variable)
+		}
+	}
+
+	return c, nil
+}
+
+// merger is an interface that must be implemented by types that are
+// merge-able. This simplifies the implementation of Merge for the various
+// components of a Config.
+type merger interface {
+	mergerName() string
+	mergerMerge(merger) merger
+}
+
+// mergeSlice merges a slice of mergers.
+func mergeSlice(m1, m2 []merger) []merger {
+	r := make([]merger, len(m1), len(m1)+len(m2))
+	copy(r, m1)
+
+	m := map[string]struct{}{}
+	for _, v2 := range m2 {
+		// If we already saw it, just append it because its a
+		// duplicate and invalid...
+		name := v2.mergerName()
+		if _, ok := m[name]; ok {
+			r = append(r, v2)
+			continue
+		}
+		m[name] = struct{}{}
+
+		// Find an original to override
+		var original merger
+		originalIndex := -1
+		for i, v := range m1 {
+			if v.mergerName() == name {
+				originalIndex = i
+				original = v
+				break
+			}
+		}
+
+		var v merger
+		if original == nil {
+			v = v2
+		} else {
+			v = original.mergerMerge(v2)
+		}
+
+		if originalIndex == -1 {
+			r = append(r, v)
+		} else {
+			r[originalIndex] = v
+		}
+	}
+
+	return r
+}