cfg: Adjust max context size based on injected prompt Close #2424

c4f119ebf9f2e7211f8524557baf24639084c237

Cohee <18619528+Cohee1207@users.noreply.github.com>

public/script.js+17 -4 Viewed

+        }
+    }
 +    // Fetches the combined prompt for both negative and positive prompts
 +    const cfgGuidanceScale = getGuidanceScale();
 +    const useCfgPrompt = cfgGuidanceScale && cfgGuidanceScale.value !== 1;
++
 +    // Adjust max context based on CFG prompt to prevent overfitting
 +    if (useCfgPrompt) {
 +        const negativePrompt = getCfgPrompt(cfgGuidanceScale, true, true)?.value || '';
 +        const positivePrompt = getCfgPrompt(cfgGuidanceScale, false, true)?.value || '';
 +        if (negativePrompt || positivePrompt) {
 +            const previousMaxContext = this_max_context;
 +            const [negativePromptTokenCount, positivePromptTokenCount] = await Promise.all([getTokenCountAsync(negativePrompt), getTokenCountAsync(positivePrompt)]);
 +            const decrement = Math.max(negativePromptTokenCount, positivePromptTokenCount);
 +            this_max_context -= decrement;
 +            console.log(`Max context reduced by ${decrement} tokens of CFG prompt (${previousMaxContext} -> ${this_max_context})`);
 +        }
 +    }
++
     console.log(`Core/all messages: ${coreChat.length}/${chat.length}`);
     // kingbri MARK: - Make sure the prompt bias isn't the same as the user bias

         setPromptString();
+    }
 -    // Fetches the combined prompt for both negative and positive prompts
 -    const cfgGuidanceScale = getGuidanceScale();
 -    const useCfgPrompt = cfgGuidanceScale && cfgGuidanceScale.value !== 1;
+-
     // For prompt bit itemization
     let mesSendString = '';

public/scripts/cfg-scale.js+9 -3 Viewed

+    }
+}
 -// Gets the CFG prompt
 +/**
 -export function getCfgPrompt(guidanceScale, isNegative) {
 + * Gets the CFG prompt based on the guidance scale.
 + * @param {{type: number, value: number}} guidanceScale The CFG guidance scale
 + * @param {boolean} isNegative Whether to get the negative prompt
 + * @param {boolean} quiet Whether to suppress console output
 + * @returns {{value: string, depth: number}} The CFG prompt and insertion depth
 + */
 +export function getCfgPrompt(guidanceScale, isNegative, quiet = false) {
     let splitCfgPrompt = [];
     const cfgPromptCombine = chat_metadata[metadataKeys.prompt_combine] ?? [];

     const customSeparator = getCustomSeparator();
     const combinedCfgPrompt = splitCfgPrompt.filter((e) => e.length > 0).join(customSeparator);
     const insertionDepth = chat_metadata[metadataKeys.prompt_insertion_depth] ?? 1;
     !quiet && console.log(`Setting CFG with guidance scale: ${guidanceScale.value}, negatives: ${combinedCfgPrompt}`);
     return {
         value: combinedCfgPrompt,