Godeps, vendor: convert dependency management to trash (#3198)

This commit converts the dependency management from Godeps to the vendor
folder, also switching the tool from godep to trash. Since the upstream tool
lacks a few features proposed via a few PRs, until those PRs are merged in
(if), use github.com/karalabe/trash.

You can update dependencies via trash --update.

All dependencies have been updated to their latest version.

Parts of the build system are reworked to drop old notions of Godeps and
invocation of the go vet command so that it doesn't run against the vendor
folder, as that will just blow up during vetting.

The conversion drops OpenCL (and hence GPU mining support) from ethash and our
codebase. The short reasoning is that there's noone to maintain and having
opencl libs in our deps messes up builds as go install ./... tries to build
them, failing with unsatisfied link errors for the C OpenCL deps.

golang.org/x/net/context is not vendored in. We expect it to be fetched by the
user (i.e. using go get). To keep ci.go builds reproducible the package is
"vendored" in build/_vendor.

1 files changed, 114 insertions, 0 deletions

diff --git a/vendor/github.com/hashicorp/golang-lru/lru.go b/vendor/github.com/hashicorp/golang-lru/lru.go
new file mode 100644
index 000000000..a6285f989
--- /dev/null
+++ b/vendor/github.com/hashicorp/golang-lru/lru.go
@@ -0,0 +1,114 @@
+// This package provides a simple LRU cache. It is based on the
+// LRU implementation in groupcache:
+// https://github.com/golang/groupcache/tree/master/lru
+package lru
+
+import (
+	"sync"
+
+	"github.com/hashicorp/golang-lru/simplelru"
+)
+
+// Cache is a thread-safe fixed size LRU cache.
+type Cache struct {
+	lru  *simplelru.LRU
+	lock sync.RWMutex
+}
+
+// New creates an LRU of the given size
+func New(size int) (*Cache, error) {
+	return NewWithEvict(size, nil)
+}
+
+// NewWithEvict constructs a fixed size cache with the given eviction
+// callback.
+func NewWithEvict(size int, onEvicted func(key interface{}, value interface{})) (*Cache, error) {
+	lru, err := simplelru.NewLRU(size, simplelru.EvictCallback(onEvicted))
+	if err != nil {
+		return nil, err
+	}
+	c := &Cache{
+		lru: lru,
+	}
+	return c, nil
+}
+
+// Purge is used to completely clear the cache
+func (c *Cache) Purge() {
+	c.lock.Lock()
+	c.lru.Purge()
+	c.lock.Unlock()
+}
+
+// Add adds a value to the cache.  Returns true if an eviction occurred.
+func (c *Cache) Add(key, value interface{}) bool {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	return c.lru.Add(key, value)
+}
+
+// Get looks up a key's value from the cache.
+func (c *Cache) Get(key interface{}) (interface{}, bool) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	return c.lru.Get(key)
+}
+
+// Check if a key is in the cache, without updating the recent-ness
+// or deleting it for being stale.
+func (c *Cache) Contains(key interface{}) bool {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	return c.lru.Contains(key)
+}
+
+// Returns the key value (or undefined if not found) without updating
+// the "recently used"-ness of the key.
+func (c *Cache) Peek(key interface{}) (interface{}, bool) {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	return c.lru.Peek(key)
+}
+
+// ContainsOrAdd checks if a key is in the cache  without updating the
+// recent-ness or deleting it for being stale,  and if not, adds the value.
+// Returns whether found and whether an eviction occurred.
+func (c *Cache) ContainsOrAdd(key, value interface{}) (ok, evict bool) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	if c.lru.Contains(key) {
+		return true, false
+	} else {
+		evict := c.lru.Add(key, value)
+		return false, evict
+	}
+}
+
+// Remove removes the provided key from the cache.
+func (c *Cache) Remove(key interface{}) {
+	c.lock.Lock()
+	c.lru.Remove(key)
+	c.lock.Unlock()
+}
+
+// RemoveOldest removes the oldest item from the cache.
+func (c *Cache) RemoveOldest() {
+	c.lock.Lock()
+	c.lru.RemoveOldest()
+	c.lock.Unlock()
+}
+
+// Keys returns a slice of the keys in the cache, from oldest to newest.
+func (c *Cache) Keys() []interface{} {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	return c.lru.Keys()
+}
+
+// Len returns the number of items in the cache.
+func (c *Cache) Len() int {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+	return c.lru.Len()
+}