Add support for forwarding stdin data to server, and getting stdout and stderr from server #4
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| * Reads a string from the socket, reading first 2 bytes to get its length and | ||
| * then the string itself. | ||
| */ | ||
| ssize_t readDelimitedString(SOCKET socket, char *buffer, size_t bufferSize) { |
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This function is basically used to read the stdout and stderr messages sent from the server.
| uint16_t outputLength = 0; | ||
| if (readSocket(socket, &outputLength, sizeof(uint16_t)) < (int)sizeof(uint16_t)) { | ||
| printSocketError("ERROR: Error reading from socket"); | ||
| return -1; | ||
| } | ||
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| if (outputLength > bufferSize) { | ||
| fprintf(stderr, "ERROR: received string is bigger than buffer (%d > %zu)", outputLength, bufferSize); | ||
| return -1; | ||
| } |
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This reads the length of the stdout/stderr data to be received. It's encoded in 2 bytes (uint16_t).
| size_t totalBytesRead = 0; | ||
| ssize_t bytesRead = 0; | ||
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| // Read output from server | ||
| do { | ||
| bytesRead = readSocket(socket, buffer + totalBytesRead, outputLength - totalBytesRead); | ||
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| if (bytesRead == -1) { | ||
| printSocketError("ERROR: Error reading from socket"); | ||
| return -1; | ||
| } | ||
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| totalBytesRead += bytesRead; | ||
| } while (bytesRead > 0); | ||
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| buffer[totalBytesRead] = '\0'; |
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This reads the actual data, and appends a \0 at the end.
| const buffer = Buffer.alloc(2, 0) | ||
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| // Send stdout | ||
| buffer.writeUInt16LE(stdout.length, 0) |
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writeUInt16LE assumes the trampoline (and tests) will always run in little-endian machines. In the unlikely scenario where we support big-endian architectures, we should revisit this (or the trampoline, to make sure it always reads the bytes in the right order).
| // Don't send anything and just close the socket after the trampoline is | ||
| // done forwarding data. | ||
| socket.end() | ||
| async function configureTrampolineServer(stdout = '', stderr = '') { |
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Unfortunately this cannot be a beforeEach function (or I didn't see how), since we need to pass parameters when the server is created 😞
| const process = execFile(trampolinePath, ['baz'], opts, function ( | ||
| err, | ||
| stdout, | ||
| stderr | ||
| ) { | ||
| if (!err) { | ||
| resolve({ stdout, stderr, exitCode: 0 }) | ||
| return | ||
| } | ||
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| reject(err) | ||
| }) | ||
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| process.stdin.end( | ||
| 'This is a test\nWith a multiline\nStandard input text', | ||
| 'utf-8' | ||
| ) |
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All this promise dance is needed to inject data to the trampoline via stdin.
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Another thing to consider: right now the buffer length is 4KB, which means that will be the limit of the commit message (+ some additional info like author and ancestors) for commit signing. Maybe we should bump that a bit? |
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Superseded by #36 |
This PR introduces a few changes:
stdinand forwards it to the server.