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Processing Pipeline Overview

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πŸšͺ Stage 1: Transport Layer Processing

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HTTP Transport Flow

Key Processing Steps:
  1. Request Reception - FastHTTP server receives request
  2. Header Processing - Extract authentication, content-type, custom headers
  3. Body Parsing - JSON unmarshaling with schema validation
  4. Request Transformation - Convert to internal BifrostRequest schema
  5. Context Creation - Build request context with metadata
Performance Characteristics:
  • Parsing Time: ~2.1ΞΌs for typical requests
  • Validation Overhead: ~400ns for schema checks
  • Memory Allocation: Zero-copy where possible

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Go SDK Flow

Advantages:
  • Zero Serialization - Direct Go struct passing
  • Type Safety - Compile-time validation
  • Lower Latency - No HTTP/JSON overhead
  • Memory Efficiency - No intermediate allocations

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🎯 Stage 2: Request Routing & Load Balancing

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Provider Selection Logic

Key Selection Algorithm: 
// Weighted random key selection
type KeySelector struct {
    keys    []APIKey
    weights []float64
    total   float64
}

func (ks *KeySelector) SelectKey() *APIKey {
    r := rand.Float64() * ks.total
    cumulative := 0.0

    for i, weight := range ks.weights {
        cumulative += weight
        if r <= cumulative {
            return &ks.keys[i]
        }
    }
    return &ks.keys[len(ks.keys)-1]
}
Performance Metrics:
  • Key Selection Time: ~10ns (constant time)
  • Health Check Overhead: ~50ns (cached results)
  • Fallback Decision: ~25ns (configuration lookup)

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πŸ”Œ Stage 3: Plugin Pipeline Processing

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Pre-Processing Hooks

Plugin Execution Model: 
type PluginManager struct {
    plugins []Plugin
}

func (pm *PluginManager) ExecutePreHooks(
    ctx BifrostContext,
    req *BifrostRequest,
) (*BifrostRequest, *BifrostError) {
    for _, plugin := range pm.plugins {
        modifiedReq, err := plugin.ProcessRequest(ctx, req)
        if err != nil {
            return nil, err
        }
        req = modifiedReq
    }
    return req, nil
}
Plugin Types & Performance:
Plugin TypeProcessing TimeMemory ImpactFailure Mode
Authentication~1-5ΞΌsMinimalReject request
Rate Limiting~500nsCache-basedThrottle/reject
Request Transform~2-10ΞΌsCopy-on-writeContinue with original
Monitoring~200nsAppend-onlyContinue silently

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πŸ› οΈ Stage 4: MCP Tool Discovery & Integration

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Tool Discovery Process

Tool Integration Algorithm: 
func (mcpm *MCPManager) EnhanceRequest(
    ctx BifrostContext,
    req *BifrostRequest,
) (*BifrostRequest, error) {
    // Extract tool filtering from context
    includeClients := ctx.GetStringSlice("mcp-include-clients")
    excludeClients := ctx.GetStringSlice("mcp-exclude-clients")
    includeTools := ctx.GetStringSlice("mcp-include-tools")
    excludeTools := ctx.GetStringSlice("mcp-exclude-tools")

    // Get available tools
    availableTools := mcpm.getAvailableTools(includeClients, excludeClients)

    // Filter tools
    filteredTools := mcpm.filterTools(availableTools, includeTools, excludeTools)

    // Inject into request
    if req.Params == nil {
        req.Params = &ModelParameters{}
    }
    req.Params.Tools = append(req.Params.Tools, filteredTools...)

    return req, nil
}
MCP Performance Impact:
  • Tool Discovery: ~100-500ΞΌs (cached after first request)
  • Tool Filtering: ~50-200ns per tool
  • Request Enhancement: ~1-5ΞΌs depending on tool count

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πŸ’Ύ Stage 5: Memory Pool Management

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Object Pool Lifecycle

Memory Pool Implementation: 
type MemoryPools struct {
    channelPool  sync.Pool
    messagePool  sync.Pool
    responsePool sync.Pool
    bufferPool   sync.Pool
}

func (mp *MemoryPools) GetChannel() *ProcessingChannel {
    if ch := mp.channelPool.Get(); ch != nil {
        return ch.(*ProcessingChannel)
    }
    return NewProcessingChannel()
}

func (mp *MemoryPools) ReturnChannel(ch *ProcessingChannel) {
    ch.Reset() // Clear previous data
    mp.channelPool.Put(ch)
}

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βš™οΈ Stage 6: Worker Pool Processing

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Worker Assignment & Execution

Worker Pool Architecture: 
type ProviderWorkerPool struct {
    workers    chan *Worker
    queue      chan *ProcessingJob
    config     WorkerPoolConfig
    metrics    *PoolMetrics
}

func (pwp *ProviderWorkerPool) ProcessRequest(job *ProcessingJob) {
    // Get worker from pool
    worker := <-pwp.workers

    go func() {
        defer func() {
            // Return worker to pool
            pwp.workers <- worker
        }()

        // Process request
        result := worker.Execute(job)
        job.ResultChan <- result
    }()
}

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🌐 Stage 7: Provider API Communication

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HTTP Request Execution

Request Preparation Pipeline: 
func (w *ProviderWorker) ExecuteRequest(job *ProcessingJob) *ProviderResponse {
    // Prepare HTTP request
    httpReq := w.prepareHTTPRequest(job.Request)

    // Add authentication
    w.addAuthentication(httpReq, job.APIKey)

    // Execute with timeout
    ctx, cancel := context.WithTimeout(context.Background(), job.Timeout)
    defer cancel()

    httpResp, err := w.httpClient.Do(httpReq.WithContext(ctx))
    if err != nil {
        return w.handleError(err, job)
    }

    // Parse response
    return w.parseResponse(httpResp, job)
}

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πŸ”„ Stage 8: Tool Execution & Response Processing

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MCP Tool Execution Flow

Tool Execution Pipeline: 
func (mcp *MCPProcessor) ProcessToolCalls(
    response *ProviderResponse,
) (*ProviderResponse, error) {
    toolCalls := mcp.extractToolCalls(response)
    if len(toolCalls) == 0 {
        return response, nil
    }

    // Execute tools concurrently
    results := make(chan ToolResult, len(toolCalls))
    for _, toolCall := range toolCalls {
        go func(tc ToolCall) {
            result := mcp.executeTool(tc)
            results <- result
        }(toolCall)
    }

    // Collect results
    toolResults := make([]ToolResult, 0, len(toolCalls))
    for i := 0; i < len(toolCalls); i++ {
        toolResults = append(toolResults, <-results)
    }

    // Enhance response
    return mcp.enhanceResponse(response, toolResults), nil
}

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πŸ“€ Stage 9: Post-Processing & Response Formation

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Plugin Post-Processing

Response Enhancement Pipeline: 
func (pm *PluginManager) ExecutePostHooks(
    ctx BifrostContext,
    req *BifrostRequest,
    resp *BifrostResponse,
) (*BifrostResponse, error) {
    for _, plugin := range pm.plugins {
        enhancedResp, err := plugin.ProcessResponse(ctx, req, resp)
        if err != nil {
            // Log error but continue processing
            pm.logger.Warn("Plugin post-processing error", "plugin", plugin.Name(), "error", err)
            continue
        }
        resp = enhancedResp
    }
    return resp, nil
}

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Response Serialization

Next Step: Deep dive into the concurrency model in Concurrency.