oracle/graal · error · IOException

Invalid replay string table index

Error message

Invalid replay string table index

What it means

IOException thrown by BinaryReplayCodec.ReadState.stringAt when a replay data stream references a string table index that is negative or >= the current table size. The binary replay format resolves strings by index into a table built incrementally during decoding; an out-of-range index means the stream is corrupt, truncated, or was written by an incompatible codec version.

Solutions

  1. Regenerate the replay file with the exact compiler build used for replay.
  2. Verify the file is complete and unmodified (checksum/re-copy) and retry.
  3. If you must replay across versions, re-record profiles on the current build instead of reusing old ones.
Defensive patterns

Strategy: validation

Validate before calling

// Validate replay file before use: writer header/version must match reader build, and file must be complete
Path p = Paths.get(replayFile);
long expected = Long.parseLong(Files.readString(p.resolveSibling(p.getFileName() + ".size"))); // emitted by capture tooling
if (Files.size(p) != expected) {
    throw new IOException("Replay file truncated: " + p);
}

Try / catch

try {
    replayCodec.decode(input);
} catch (IOException e) {
    if (e.getMessage().startsWith("Invalid replay string table index")) {
        // regenerate the replay file on this build; do not retry the same bytes
    }
    throw e;
}

Prevention

When it happens

Trigger: Reading a replay file (-Dgraal.ReplayCompilation / replay tooling) where a record refers to a string index not yet defined (or beyond EOF), or the file was produced by a compiler whose BinaryReplayCodec wrote a different table layout.

Common situations: Replaying compilation profiles across compiler builds (table order changed); truncated file transfers; bit rot in stored .glog/replay artifacts; hand-editing replay files.

Related errors

AI-assisted analysis of oracle/graal@a66e9ccd1d (2026-08-14). Data as JSON: /api/errors/7e572fd9e91df4d7. Report an issue: GitHub.

Appendix: source

Thrown at compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/hotspot/replaycomp/BinaryReplayCodec.java:252

    private final class ReadState {
        private final CompilationProxies.ProxyFactory proxyFactory;
        private final ArrayList<String> stringTable = new ArrayList<>();
        private final ArrayList<CompilationProxy.SymbolicMethod> methodTable = new ArrayList<>();
        private final Object[] singletonProxies = new Object[registrations.length];

        @SuppressWarnings("unchecked") private final EconomicMap<Integer, Object>[] instanceProxies = (EconomicMap<Integer, Object>[]) new EconomicMap<?, ?>[registrations.length];

        private Architecture architecture = hostTarget.arch;

        private ReadState(CompilationProxies.ProxyFactory proxyFactory) {
            this.proxyFactory = proxyFactory;
            stringTable.add(null);
        }

        private String stringAt(int index) throws IOException {
            if (index < 0 || index >= stringTable.size()) {
                throw new IOException("Invalid replay string table index " + index);
            }
            return stringTable.get(index);
        }

        private void defineString(int index, String value) throws IOException {
            if (index != stringTable.size()) {
                throw new IOException("Invalid replay string definition index " + index);
            }
            stringTable.add(value);
        }

        private CompilationProxy.SymbolicMethod methodAt(int index) throws IOException {
            if (index < 0 || index >= methodTable.size()) {
                throw new IOException("Invalid replay symbolic method index " + index);
            }
            return methodTable.get(index);
        }

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