From 95e271d98f0b5717bde2b7e5c4c7639c19fd3763 Mon Sep 17 00:00:00 2001
From: Bruce MacDonald <brucewmacdonald@gmail.com>
Date: Mon, 17 Mar 2025 15:11:15 -0700
Subject: [PATCH] runner: remove cache prompt flag from ollama runner (#9826)

We do not need to bypass the prompt caching in the ollama runner yet, as
only embedding models needed to bypass the prompt caching. When embedding
models are implemented they can skip initializing this cache completely.
---
 runner/ollamarunner/cache.go      |   7 +-
 runner/ollamarunner/cache_test.go | 128 ++++++++++++++++++++++++++++++
 runner/ollamarunner/runner.go     |   2 +-
 3 files changed, 130 insertions(+), 7 deletions(-)

diff --git a/runner/ollamarunner/cache.go b/runner/ollamarunner/cache.go
index adcb3f738..cf5e6b911 100644
--- a/runner/ollamarunner/cache.go
+++ b/runner/ollamarunner/cache.go
@@ -89,7 +89,7 @@ type InputCacheSlot struct {
 	lastUsed time.Time
 }
 
-func (c *InputCache) LoadCacheSlot(prompt []input.Input, cachePrompt bool) (*InputCacheSlot, []input.Input, error) {
+func (c *InputCache) LoadCacheSlot(prompt []input.Input) (*InputCacheSlot, []input.Input, error) {
 	var slot *InputCacheSlot
 	var numPast int32
 	var err error
@@ -107,11 +107,6 @@ func (c *InputCache) LoadCacheSlot(prompt []input.Input, cachePrompt bool) (*Inp
 		return nil, nil, err
 	}
 
-	// TODO (brucemacd): cachePrompt is always true for completion, but false for embedding, can this be improved?
-	if !cachePrompt {
-		numPast = 0
-	}
-
 	slot.InUse = true
 	slot.lastUsed = time.Now()
 
diff --git a/runner/ollamarunner/cache_test.go b/runner/ollamarunner/cache_test.go
index 0a1b73f5a..f8925d119 100644
--- a/runner/ollamarunner/cache_test.go
+++ b/runner/ollamarunner/cache_test.go
@@ -297,3 +297,131 @@ func TestShiftDiscard(t *testing.T) {
 		})
 	}
 }
+
+func TestLoadCacheSlot(t *testing.T) {
+	tests := []struct {
+		name           string
+		cache          InputCache
+		prompt         []input.Input
+		wantErr        bool
+		expectedSlotId int
+		expectedPrompt int // expected length of remaining prompt
+	}{
+		{
+			name: "Basic cache hit - single user",
+			cache: InputCache{
+				multiUserCache: false,
+				slots: []InputCacheSlot{
+					{
+						Id:       0,
+						Inputs:   []input.Input{{Token: 1}, {Token: 2}},
+						InUse:    false,
+						lastUsed: time.Now().Add(-time.Second),
+					},
+					{
+						Id:       1,
+						Inputs:   []input.Input{},
+						InUse:    false,
+						lastUsed: time.Now().Add(-2 * time.Second),
+					},
+				},
+			},
+			prompt:         []input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
+			wantErr:        false,
+			expectedSlotId: 0,
+			expectedPrompt: 1, // Only token 3 remains
+		},
+		{
+			name: "Basic cache hit - multi user",
+			cache: InputCache{
+				multiUserCache: true,
+				slots: []InputCacheSlot{
+					{
+						Id:       0,
+						Inputs:   []input.Input{{Token: 1}, {Token: 2}},
+						InUse:    false,
+						lastUsed: time.Now().Add(-time.Second),
+					},
+					{
+						Id:       1,
+						Inputs:   []input.Input{},
+						InUse:    false,
+						lastUsed: time.Now().Add(-2 * time.Second),
+					},
+				},
+			},
+			prompt:         []input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
+			wantErr:        false,
+			expectedSlotId: 0,
+			expectedPrompt: 1, // Only token 3 remains
+		},
+		{
+			name: "Exact match - leave one input",
+			cache: InputCache{
+				multiUserCache: false,
+				slots: []InputCacheSlot{
+					{
+						Id:       0,
+						Inputs:   []input.Input{{Token: 1}, {Token: 2}},
+						InUse:    false,
+						lastUsed: time.Now().Add(-time.Second),
+					},
+				},
+			},
+			prompt:         []input.Input{{Token: 1}, {Token: 2}},
+			wantErr:        false,
+			expectedSlotId: 0,
+			expectedPrompt: 1, // Should leave 1 token for sampling
+		},
+		{
+			name: "No available slots",
+			cache: InputCache{
+				multiUserCache: false,
+				slots: []InputCacheSlot{
+					{
+						Id:       0,
+						Inputs:   []input.Input{{Token: 1}, {Token: 2}},
+						InUse:    true,
+						lastUsed: time.Now().Add(-time.Second),
+					},
+				},
+			},
+			prompt:         []input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
+			wantErr:        true,
+			expectedSlotId: -1,
+			expectedPrompt: -1,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			slot, remainingPrompt, err := tt.cache.LoadCacheSlot(tt.prompt)
+
+			// Check error state
+			if (err != nil) != tt.wantErr {
+				t.Errorf("LoadCacheSlot() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+
+			if tt.wantErr {
+				return // Skip further checks if we expected an error
+			}
+
+			// Verify slot ID
+			if slot.Id != tt.expectedSlotId {
+				t.Errorf("LoadCacheSlot() slot ID = %v, expected %v", slot.Id, tt.expectedSlotId)
+			}
+
+			// Verify slot is now marked in use
+			if !slot.InUse {
+				t.Errorf("LoadCacheSlot() slot not marked InUse")
+			}
+
+			// Verify remaining prompt length
+			if len(remainingPrompt) != tt.expectedPrompt {
+				t.Errorf("LoadCacheSlot() remaining prompt length = %v, expected %v",
+					len(remainingPrompt), tt.expectedPrompt)
+			}
+		})
+	}
+}
diff --git a/runner/ollamarunner/runner.go b/runner/ollamarunner/runner.go
index d4c24556c..98fcf2c04 100644
--- a/runner/ollamarunner/runner.go
+++ b/runner/ollamarunner/runner.go
@@ -590,7 +590,7 @@ func (s *Server) completion(w http.ResponseWriter, r *http.Request) {
 	found := false
 	for i, sq := range s.seqs {
 		if sq == nil {
-			seq.cache, seq.inputs, err = s.cache.LoadCacheSlot(seq.inputs, true)
+			seq.cache, seq.inputs, err = s.cache.LoadCacheSlot(seq.inputs)
 			if err != nil {
 				s.mu.Unlock()
 				http.Error(w, fmt.Sprintf("Failed to load cache: %v", err), http.StatusInternalServerError)