Optimize shell subprocess spawning and add file I/O caching

[Copilot]

Multiple performance bottlenecks identified: shell script spawned Python interpreter 4 times per execution (~200-400ms overhead), config file read on every access without caching, and inefficient URL parameter construction.

Changes

Shell script (query-token-balance.sh)

• Replace Python subprocess calls with jq for JSON operations
• Consolidate config loading from 4 Python invocations to 1 jq call

Python (etherscan_common.py)

• Add module-level config caching (mirrors existing messages cache pattern)
• Cache on default path only; custom paths bypass cache

JavaScript (etherscan-common.js)

• Use URLSearchParams constructor instead of loop-based parameter appending

Python (query-token-balance.py)

• Cache formatted response to eliminate duplicate serialization

Example

Before:

# Multiple Python subprocess spawns
load_messages() {
    python3 -c "import json, os; messages = json.load(...)..."
}
status=$(echo "$response" | grep -o '"status":"[^"]*"' | cut -d'"' -f4)

After:

# Single jq calls
load_messages() {
    jq -c '.' "$SCRIPT_DIR/etherscan-messages.json"
}
status=$(echo "$response" | jq -r '.status // ""')

Original prompt

Identify and suggest improvements to slow or inefficient code.

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.